Rules for the Sengoku Jidai: Number Crunching

I had the the outcome of the last battle rattling round my head all day so decided to crunch some numbers this evening to see how combats would play out in numbers. I will of course play things out on the table again but wanted some cold stats for modelling different combats by running hundreds of thousands of iterations to see how they resolved.

This is pretty crunchy so no shame if you don’t want to read it all. If you skip to the end I have some reflections on the above battle report in light of my findings.

Using my current close combat rules, two standard units battling it out would take on average 9 rounds of combat for one side to destroy the other. Each turn would typically involve two rounds of combat in this scenario so an average of 4.5 turns. This number was skewed a bit by some fairly insane runs going up to 65+ rounds of combat! These are obviously unrealistic in an actual game, and combats lasting more than 16 rounds only comprised 11% of the results set, so excluding these outliers the average drops to 6 rounds of combat, or 3 turns. So we can assume 6-8 rounds of combat would be average, with 16% of engagements ending in one unit being destroyed in the first two rounds.

This is assuming both sides just batter away at each other and as one of the combat outcomes is that both withdraw, this assumes they then use their next activation to charge in again and re-engage. Which raises an interesting point. In these exchanges, around 80% of combats will end in a withdrawal, on average after 2 rounds of combat. Withdrawal usually favours the charger as it will push the defender back, meaning if the attacker gets to go again next they can possibly push the defender back further.

In the above scenario of two standard units a typical conflict between them with nothing else interfering may see unit A charge unit B, they resolve a round of combat, it is indecisive but holds then engaged. Unit B activates and they have another round of combat which ends in both withdrawing. Next turn unit B may activate first and charge unit A. They have a round of combat which ends still locked in combat. Next round they withdraw, then charge again. This will continue for another few rounds unit one is destroyed, either by accumulated damage or a superior shock roll. This seems pretty reasonable. Two evenly matched units pushing each other across the battlefield, each clash lasting around 2 rounds of combat before a withdrawal and with around a 16% chance of outright destroying the opponent each time, or a 50% chance of inflicting damage before withdrawing. Each unit has 3 “hits” they can take and each reduces their effectiveness in the next combat round, so that can mount up.

In difficult terrain this would take on average four times as long, with a much more statistically significant proportion of results taking more than 16 rounds of combat, at over 50%. This explains the slog at the river I experienced. It required piling a lot of units into the fight and multiple rounds of combat for things to resolve.

However, increasing the number of units involved rapidly increases the lethality of combat. Going back to the example of two standard units in normal terrain, adding a support each to the combating units doubles the chance of a unit being destroyed before a withdrawal. A 2v2 fight will end in destruction before withdrawal half the time and a 4v4 will see victory or defeat 80% of the time in a single round. This also only deals with standard units, when you add into the mix larger and smaller units with different varieties of stats things can get interesting fast.

This does match what I want to do with the game. Individual units are not generally all that strong, but when used in the right combination they can be pretty effective. Using my current stat lines, two small detachments of mixed Ashigaru would essentially poke away at each other until the cows come home without ever really risking causing serious harm. This fits fairly well with what I’d expect their behaviour to be without any samurai about to push for a more brutal outcome. They’d likely wave their pointy ends at each other, withdraw for a few pot shots, maybe get up the nerve to charge, poke a bit, withdraw, etc. But add a samurai support into the mix and the damage starts ramping up, with 50% of engagements resulting in damage or destruction before withdrawal.

This modelling lets me play about with stat lines a fair bit. For instance, a unit of samurai against a unit of ashigaru would have a hard enough time of it. While there is little risk of them being hurt themselves, it would take some time to wear the ashigaru down enough to finish them, which seems reasonable given the difficulty of breaking a formed up wall of pikes with just individuals wielding spears and swords. However, ashigaru and samurai used in coordination, either in a combined sonae unit or small kumi detachments working in combination, are a force to be reckoned with.

Another other interesting stat I’ve been able to work out us that all other things being equal, the charger into an engagement will come out on top 55% of the time, which gives them a small advantage but not immediately decisive. This is around what I was aiming for.

I may in time expand the modelling to include ranged combat. I’d be particularly interested to see how useful closing fire is and if the trade off is reasonable enough to make it an effective tool in the players decision making process.

If you got this far, well done! So what does this all mean in relation to the battle I just fought and future conflicts? I think it’s mostly good things. My concern was that close combat could be too much of a grind, when I wanted it to be decisive, however on reflection that was more to do with the circumstances. Fighting in the difficult terrain was a grind, but it should be. It was brought to a resolution by throwing masses of troops in in a high risk series of exchanges. A wily general may have taken a different tact though.

The Oda could have done themselves a favour by concentrating their attack more. Their overextension allowed them to get good ground quickly but not support it, which was their undoing. Had they focused their attack in the North where they had most success rather than trying to fight the whole length of the river, the battle may have gone another way. Even late on when one unit managed to break through, had they pulled some units off the line to support it they may have been able to strike directly at the Asai general rather than getting bogged down in the river.

For the Asai, they missed a trick against the Oda overextension, rather than drawing the Oda further into the plain and cutting them off, they pushed them back to the river where they meet their supports and dug in. Has the Asai been a little less risk averse and let the Oda in deeper, they could have easily encircled the Oda vanguard and destroyed it.

What this tells me though is that the rules are working in a way I had hoped for. There’s a few small tweaks to shake out but on the whole they’re giving me options to work with and I’m excited to try again and see what happens. For my next game I’ll likely try a more open battlefield, but I may return to this river valley scenario sometime and see what happens with different tactics.

Thanks for reading,


Battle Report – Oda vs Asai

Having spent a fair bit of time lately writing up my rules for warfare in the Sengoku Jidai (see here and here for more information) I thought it was time to finally get a battle on the table rather than the pencil and paper affairs I’d done previously. As I’ve no figures for the period yet, I made up some counter that I printed (after several hours of battling with the printer) onto cardboard. The original plan was for Mori vs Oda, but as the printer refused to print anything red, I rebranded the Mori as Asai for the game. Oda in yellow, Asai in blue. I’ve reworked the morale system into a loyalty system instead, as well as added a few rule tweaks to different aspects of it. Lightning Bolts = Wavering, Broken Hearts = Disloyal, No Entry = Fatigued. Small yellow dice = Positive Authority, small black dice = Negative Authority. The pile of white counters are just pieces I used to track orders.

The Oda force arrayed for battle with the Oda general encamped on a small hill overlooking the advance.
The Asai forces present a more orderly line, with the Asai general in the midst of his troops on the hill to the right.

The battle field consists of a fordable river running down the centre, a series of scattered hills throughout and an impassible forest to the south. Both armies were evenly matched (though with slightly different stat distributions) so I ran this as a straight encounter battle, the two sides trying to destroy each other. Each army consists of three divisions and the overall general as their own separate division to themselves.

Japan is a particularly mountainous land so many of the flat areas feature rivers and forests in abundance.

The rules use a random activation system for each command. In the game opening the Asai got the first few activations but were slow to make use of them, moving their troops up slowly. The Oda on the other hand rushed ahead, stretching out their forces to get to the defensive river first and ford it.

The Asai begin a gradual advance, with the third division around the general holding their position until they knew where they could be best used.
The Oda rush towards the river hoping to seize the defensive position early.

The Oda move up to the river rapidly and cross to take up position on the large hilltop overlooking the river valley, though doing so leaves their lines extended. The Asai third division, who had thusfar been holding back in reserve, sweep down off their hill and into the valley to meet the rapid Oda advance.

Divisions circled here showing how stretched out the Oda advance is.
The Asai reserve moves up to bolster the forces approaching the river.

With the Oda gun teams taking up position on the hill the Asai attempt to dislodge them with their leading ashigaru detachments, but the concentrated gunfire throws them back.

The Oda establish a forward position on the hill.

The two forces enter firing range across the fronts with exchanges flowing back and forth, resulting in one of the Asai ashigaru units fleeing from the field. Bolstered by the success of their compatriots down the river, the gunners on the hilltop rally and blast away at another Asai ashigaru detachment, driving them from the field. However, from behind them comes a much larger sonae force which crashes into the gunner line, forcing them back towards the river.

The Oda advance over the river and break  a couple of Asai units.

As the main body of the Oda force come up behind the vanguard, the gunners on the hill press the fight, but one of them is forced to withdraw as their morale weakens. Two detachments of Oda ashigaru rush across the hilltop and crash into the Asai ashigaru detachment in an attempt to overwhelm them.

Things aren’t looking good for the Asai.

Meanwhile, down the river, the Asai gunners batter the Oda forces, holding them at bay until the Asai main body can come up and begin pushing the overextended Oda forces back across the river. The Asai forces press forwards, driving the Oda back until they both form their battlelines across the river. Oda himself decamps in order to get closer to the action and bolster his forces with his presence.

The Asai push the unsupported Oda advance back over the river.
The Oda general mounts up and prepares to join the fight.

The battle on the hill rages on with troops piling in from all sides and the fight going back and forth, but eventually the weight of the Asai forces is too much for the Oda and they break, with their supports falling back towards the river. The Asai push ever forwards.

The Oda commit all the forces they can spare to take the hill but the Asai onslaught is overwhelming.

The battle over the river intensifies, the difficult terrain making it near impossible for one side to get the upper hand, but in the slow grind the Asai forces seem to be getting the better of their opponents. The Oda are slow to bring up their reserves, having rapidly pushed forward at the start of the battle, but when the rearguard division moves up it manages to temporarily break through the lines and attack the Asai at a weak point. This attack is eventually repelled though not without considerable damage to the Asai lines.

The Asai advance pushes the Oda units back across the river.
The Oda break through but lack the support to take the momentum of it forwards.

Nevertheless, the Asai push onwards, to the river, ever pushing the Oda forces back. The battle rages on, both sides wet, muddy and bloodied but neither breaking their resolve. As the larger sonae of the commanders on both sides bear down on each other, the final battle is joined.

The river runs red with blood as countless men fall on its banks.

The fighting is vicious and flows back and forth, neither side able to completely destroy the other. Oda himself rushes in to support his lines as he see’s it weakening, but too late.

The melee grinds back and forth, the Oda see some success in the centre, but are losing out on the flanks.

Like a line of dominoes the Oda commands crumble all along the river banks and flee from the field.


Oda is left alone facing the the might of the Asai army. He promptly turns and flees.

All in all a good first run with the rules. The printed out counters worked well for the kitchen table sized game and the opening turns of the game flowed well. Movement felt natural and the order system seemed to work well. The opening engagements of ranged combat felt right too and the stats I’d assigned worked reasonably well. I’d a mix of different unit success with stats for detachments of mixed Ashigaru and gun armed units, as well as small clans, standard clan sonae and the larger commander sonae.

I ended up abandoning the idea of Opportunity Fire. Any time that it should have been used didn’t seem right, so I’ll need to rethink it, but with the activation system the way that it is, it may not be necessary to have it at all.

The new loyalty system worked well, even though it was only a minor modification of the morale system I’d initially worked out, it felt more natural and flavourful. The only bit I’m unsure on is whether a unit should be allowed multiple rally’s per turn. In theory you can issue as many Rally Orders as you have Orders available (provided the unit is out of range of the enemy) but felt a bit strange attempting to rally over and over on one turn.

Melee was a bit of grind at times. I introduced a new support mechanic which worked well (essentially they add half their stats to the unit they’re supporting) and made the battles on the hilltop a lot more dramatic, though they still did end up taking a few turns to resolve after I “nerfed” the shock system a bit. I still think I was right to weaken shock slightly, and the hilltop battles felt generally right as new supports moved in to bolster the lines but units weakened in each exchange. The support system with the detachments worked well and gave me some ideas on using the rules for smaller scale battles too. Would need a slight change in mechanics to allow for closer support at the smaller scale, perhaps the supporting unit can contribute all their Shock. Food for thought.

The main sticking point was the battles along the river. Because of the difficult terrain they really dragged on with a slow grind and no one really had a means of gaining a greater advantage. Part of me thinks this is right, after all battles over rivers generally were a grind as both sides slogged across the water and up and down river banks pushing each other back and forth. And the Oda rearguard division bursting through a gap very nearly turned the tide, though like so many of the Oda actions, they overextended and were cut off. So I probably would want to play another game on a more open battlefield before doing any major reworks to the melee system to see if it flows well there.

The command and control system as well as the messengers and the Generals all worked nicely, with the additional authority boost the messengers gave turning the tide at a few points and giving additional focus to a part of the battle field, giving meaningful decision making to their use. The only downside is what to do with additional orders when at the point of melee when there’s little to be done. Part of me is pondering whether any “leftover” orders can be used to bolster certain melee combats at the end of the activation. This may alleviate some of the issues I had with the melee grind and give the authority aspect more prominence in the later part of the game.

All in all though I’m pretty happy. The game gave me enough different situations to really shake out the rules and I’ll be able to go back and tighten up a few aspects of it as well as ponder a few additions and tweaks.

I’m sure I’ll have more updates in future on this, but for now, I hope you’ve enjoyed this and thanks for reading,


Rules for the Sengoku Jidai: Core Mechanics

In my last post I gave a bit of background for my thinking on how a Sonae based Sengoku Jidai ruleset might work and some of my early experiments with it. To recap, the Sengoku Jidai refers to the period of civil war that devastated Japan in and around the 16th century. Armies were generally organised into sub units of mixed arms clans known as Sonae. The terrain of Japan meant warfare tended to favour looser formations and manoeuvre than would typically be seen elsewhere in the world at the time.

For the moment I’ve settled on “hit dice” as my randomisation method, namely rolling 4 dice, adding or removing dice based on situational modifiers, then counting any 6’s as a success. In this post I hope to explore some of the core mechanics I’ve been trying out; command and control, movement, combat and morale.

I am writing these into a more “technical” rules document, but wanted to lay out some of the general concepts here. At the end I will have a brief pencil and paper battle report to show how some of the mechanics play out.

Command and Control

This refers to the means in which the players actually command their armies and give orders to commanders and units. There are essentially three levels of command. The first and lowest level is the individual units, typically a mixed arm Sonae, commanded by a Samurai-daisho (military leader) a minor Daimyo (feudal lord). These commanders are abstracted into the units themselves and assumed to be dealing with the individual allocation of troops within the Sonae.

Multiple Sonae will generally be grouped together into a Te, or division. The most senior, and usually most powerful, Sonae within this division, is known as the Honjin (or headquarters Sonae), usually commanded by a senior Daimyo. This Honjin Sonae is the Commander for the entire Te, and is the one from which actions to the individual units will flow.

An army will generally consist of several of these Te with the leader of the most senior Daimyo’s Te being designated the overall Army General. Unlike the Commanders who are embedded into their Honjin Sonae, the Army General is treated as a stand alone entity based separately to a Sonae, though they will usually have one or more powerful Sonae in their own Te commanded by trusted retainers, usually including a Honjin Sonae with it’s own Commander. Typically there will be one Army General per side, but in large, multiplayer battles, there could potentially be multiple Army Generals, each leading their own set of divisions in coordination with their ally. This can lead to some fun possibilities for betrayal and treachery, as was common in the period.

These Army Generals may be in one of two states. The first is “Encamped” whereby they are based with their Maku screen and retainers, usually in a prominent but well defended position in the battle field. In this state they have powerful defensive modifiers, can send out messengers to their commanders, but cannot move themselves.

The second is “Mobile” whereby they mount up with their personal unit of bodyguard troops, known as the Hatamoto, and become a powerful unit in their own right with rapid movement but no ability to send out messengers to commanders and a greater chance of personal injury.

The fourth Battle of Kawanakajima: Takeda Shingen Vs Uesugi Kenshin - by  Dmitry Filatov. | Takeda shingen, Samurai art, Japanese history
There is a somewhat fanciful story of the great rivals Uesugi Kenshin and Takeda Shingen engaging in a brief duel when Kenshin, mounted with his Hatamoto personal guard burst into the Takeda camp and engaged an unprepared Shingen, who was forced to defend with his steel war fan until his own Hatamo could drive Kenshin off. While it likely never happened, it does provide a good example of the two different ways Generals can operate.

Given the hierarchical clan status of the armies, the loss of a Commander will generally mean the loss of an entire division, and the loss of the Army General will usually spell the loss of the entire battle. So there is a fine balance between using these as powerful offensive units, while keeping them safe from harm at risk of collapsing the army. There is some potential around loyalty and successor mechanics that may mitigate this collapse somewhat, likely a series of Morale tests for the units and a test or special trait that allows a Commander or General to have a worthy successor to take the reigns of battle, but I’ve still to shake out the details on them.

Each commander (including the general) will have an Authority value representing their right to rule and the respect they hold from their retainers. This can be a positive or negative value, depending how powerful or weak they are. This value will be used to modify the number of orders that they can give. The commanders will also have a Command Radius that extends out from their unit, with Authority increasing or decreasing the range. Any units outside this Command Radius may only be given one order per activation. Any units within the General’s Command Radius will gain a bonus to their Morale tests.

At the beginning of each turn the player will decide if their Army General is Encamped or Mobile. If Encamped then they may designate a Commander to send a messenger to. If both the General and Commander are out of range of any enemy units then this is decided with a simple 4 + Authority d6 check (success on at least one 6). If either is within range of the enemy, the check is opposed and must score more successes than the enemy to succeed. If successful, then that commander can add the general’s Authority along with their own to their next activation. I did briefly toy with having messengers as their own units that travelled across the battlefield, but it became somewhat messy and required remembering which messenger had been directed at which commander. I suspect the messenger rules will undergo further modifications in time, for instance reducing the available dice over longer distances.

Activations are dynamic. For each command a token should be placed in a bag or stack to allow for random activations. Ideally this would be a token with the clans Mon (or symbol) on it, but could equally be coloured dice or chits, a stack of cards, etc. Anything that lets the players randomly allocate command activation. Players will draw a token and whichever general that token belongs to can allocate it to a command within the army. That command then activates and performs its actions, then the next token is drawn and the process repeats. This means play can alternate back and forth between the players, or may result in one player having a run of a few activations then the other player having the same. Each command can only activate once per turn.

Kamon Symbols of Japan — Encyclopedia of Japan
The Mon of some of the better known clans in the period, this would appear prominently on banners and screens for the clan’s troops. Some of the clan names in this graphic are non-standard renditions, such as Mouri (Mori) and Houjou (Hojo).

Once activated the command rolls a single d6, adding the appropriate Authority modifiers, and that will give the number of orders that can be given that activation. Orders can then be allocated out amongst the units under command to move, engage in combat or rally. There is no limit to the number of orders that each unit can have assigned, up to the total allocated, but those units receiving a large number of orders will have to take a morale test and on failure become fatigued and unable to take any actions the following activation.

Once all the orders have been allocated, or the player doesn’t wish to allocate any more, the activation ends and the next one is drawn. Once all commands have been activated, the turn ends and the cycle begins again.


This relates to how the units actually manoeuvre around the battlefield. My plan is to keep movement fairly simple. The distance of movement is the same for all units, though certain units will be allowed an extra move such as mounted generals. I’m generally assuming the unit of movement will be around a base width, as that’s usually a decent indicator of unit and table size. Each unit will have a front quarter, a rear quarter and two flank quarters, with the boundaries extending in diagonals from the unit’s corners. When I say something is n Movements, it means n units of whatever the movement distance is. To make a movement a unit will be issued with a Move Order. This will allow them to do one of three things:

  • Move directly into their forward quarter by up to 2 Movements maintaining facing. This may include charging into contact with an enemy unit.
  • Fall back into their rear quarter by 1 Movement maintaining facing. If this is given to a unit in combat they must take a Morale check after doing so.
  • Change facing to a different quarter and make up to 1 Movement in the new direction of facing. This covers all manoeuvring, whether it be changing facing and remaining in place, or moving in a new direction.

Units may be issued any number of Move Orders so long as the commander has Orders to allocate and they begin the orders within the Command Radius of the commander.

Terrain will have some impact on movement, essentially difficult terrain will only allow one Movement forward rather than two and roads allow an extra Movement when going forward or back along it. These rules still need a bit more experimentation. It may be that difficult terrain ends all movement for that unit for that activation and they cannot be given any more Move Orders.

Charging Mounted Samurai
Massed cavalry charges were rare in Japanese warfare of the period, but small groups of mounted samurai could turn the tide of battle when striking the right place at the right time.

Given the fixed distances, the rules as written could be easily translated to a square or hex grid. I’ve been playing out test games on gridded notepaper (mostly because it’s all I have to hand with everything packed away to sell our house) and it’s worked reasonably well, but overall the fluidity of free measurement will provide a much more satisfying range of movement options.

Ranged Combat

There are two types of combat in the game. The first, and generally less effective, is Ranged Combat. This represents the proportion of bows and guns within a unit. While bows and guns of the period had a theoretical range of 300-500 metres, in reality the effective range against armour was around 50-100 metres. Over time as the proportion of guns increased, firepower became more effective, but was still primarily used as a means of defence, behind screens and fortifications, or for softening up an enemy before the charge into melee for offensive actions.

Standard Ranged Combat will work as an exchange between two units at a range of 2 Movements or less. Most units will have some means of firing, even if its just a few samurai with bows and guns. There will be modifiers available to units, typically ranging from -2 to 2 that can reflect the proportion of guns and firing capacity. In a Ranged Combat exchange, both units will roll their ranged attack dice, hitting on 6s then total up the number of hits inflicted. The default number of attack dice is four, though the modifiers mentioned previously along with a few other special conditions (e.g. firing up a hill would be -1, while firing at close range would be +1) can modify these dice up and down.

Any side that receives at least one hit must make a Morale test, which will be described later but essentially consists of throwing four dice (+/- modifiers) with at least one 6 needed for a pass. For each additional hit past the first one in the Ranged Exchange, a dice is removed from the Morale test. So if a sonae of the Ouchi engages a sonae of the Mori in a ranged attack, both players would roll their attack dice. If the Ouchi rolled three 6s and the Mori rolled one 6, then both sides would be required to take a Morale test, but the Mori would do so with 2 less dice than normal due to the two additional hits.

Failing a Morale test from a ranged attack results in a unit status change. A unit that is fresh and in good spirits will become Wavering, which will somewhat impair their ability to fight in Close Combat. A unit that is already Wavering will become Brittle, which impairs them further still. A unit that is already Brittle will break and be removed from the battle. This means a ranged exchange is unlikely to cause serious damage unless a unit is already in dire straights. There will be a Rally mechanic described later to remove these statuses.

Ranged Ashigaru
Most ranged combat was done by sub units of Ashigaru peasant soldiers armed with matchlock “teppo” guns and light weight long bows known as “yumi”, though samurai would often have guns and bows as their primary weapons well. Indeed the yumi was the traditional primary weapon of samurai in earlier periods before massed peasant infantry and firearms became the norm.

Exceptions to this standard exchange are when engaging from the flank, in which case only half your attack dice can be used, or from the rear, in which case only one attack dice can be used. There is also the possibility of Opportunity Fire, the exact details of which are still under review, but will generally allow a unit to take unopposed pot shots at anyone entering firing range. I’m still not entirely sure on this given the exchange nature of standard firing, it’s mostly a means to prevent units skipping along the front of the enemy without consequence, but I may instead implement some form of Zone of Control on movement that prevents this instead. The other type of firing is Closing Fire, which I’ll cover shortly as part of the Close Combat exchange.

Close Combat

Close combat consists of up to four phases, Charging, Closing Fire, Melee and Shock. Charging is covered under the movement rules and is a movement that ends in contact with an enemy unit. The unit that initiated the charge will gain an extra dice in the first round of Melee. If a unit is Wavering it must pass a Morale test before charging and a Brittle unit cannot charge at all.

The defending unit may choose to use Closing Fire, that is an unopposed ranged attack, i.e. only the defender rolls their attack dice. If it is successful in hitting the charger, and the charger fails the Morale test then the new status is applied, the charge will be cancelled and the charger will fall back or pull up 1 Movement short of the enemy unit. However, if the charger is unharmed, the defender will have one less attack dice to use in the following round of Melee combat. This is to simulate the delay in bringing up the melee troops while firing at the charging unit.

The Charge and Closing Fire occur as part of the normal cycle of Orders, but Melee doesn’t occur until the end of the Activation. This allows all movements and ranged attacks to be carried out first, then all close combat will be resolved.

The Melee Phase involves both participants rolling their attack dice, modified as needed, with different results depending on the outcome. If both units fail to make any successful hits, then each will fall back 1 Movement to their rear quarter. If this movement is blocked, for instance by another unit or a terrain feature, they must instead take a Morale test and apply the appropriate status if failed. If both units make the same number of hits, they remain locked in combat and nothing else happens for them until the next time one of their commands is activated. If one side manages to make more successful hits than the other, that side is considered the victor and may move onto the Shock Phase.

The Shock Phase is representative of the elite troops, such as the samurai, exploiting a weakness opened up by the melee and rushing in to try and destroy the enemy command. In the Shock Phase the victor rolls their attack dice modified by any shock modifiers they may have (typically terrain affects the impetus of the shock phase more than the melee) with the outcome depending on how many successes they have.

With one success the enemy unit is destroyed but the attacker is Fatigued.

With two successes the enemy unit is destroyed and the attacker is not Fatigued.

With three or more successes the enemy unit is destroyed, the attacker is not Fatigued and gets a bonus order to use immediately.

The number of orders may increase with increased success, to be confirmed, and the destruction on one success might be too powerful, so one success may apply a status while two success destroys, etc. These are details to be ironed out in play testing.

Artwork of battle
Combat in the period often ended in bloody and brutal close combat.

Where multiple units are engaged, all dice are rolled together. This is the most “bucket o’ dice” part of the rules, but means large engagements can be dealt with quickly, and makes multi unit melee combats very dangerous, especially if Commanders are involved.

Flank and rear attacks also behave a little differently. There is no Closing Fire when attacking a flank or rear of the unit, and the defending unit cannot use a Shock Phase if it is engaged to the flank or rear, instead if it is victorious in the Melee Phase, the attackers both fall back 1 Movement. This is because an attack at a weak point of the formation would usually be reinforced by the samurai core of the unit, meaning they’ve less momentum to carry out a destructive counter attack immediately and instead just drive the attacker off. Any unit attacking the rear gains an additional attack dice as well as that was usually the weakest point of a formation.


As mentioned in previous sections, each unit will have a certain amount of Morale that it can use to show how resilient it is to breaking. All units have the same potential Morale statuses, Wavering and Brittle, though how those statuses affect different areas of the game will vary. Morale tests are called for in a number of circumstances where the resolve of the unit needs tested. Morale tests behave the same way as other tests in the game, a number of dice, four by standard, are thrown with at least one 6 being required to make it a success. Some units may have Resilience modifiers that can increase or decrease their morale dice, and having the Army General within range can provide an extra morale boost too.

One of the orders available to a commander is a Rally Order. With this a unit that is not in attack range of an enemy unit (i.e. typically 2 Movements away) and within the Command Radius of it’s Commander, may perform a Morale test and if successful, can reduce their negative statuses. So a Brittle unit that passes it’s Rally Morale test will become Wavering, and a Wavering unit that passes loses the negative status and returns to being fresh and ready for action.

Facing this sort of devastation would shake the morale of even the loyalist of samurai, let alone the peasant masses.

There are still some balancing tests needed with morale, for instance having the presence and loss of nearby units impacting the roll or requiring additional tests, but for the moment I’m keeping it reasonably simple.

Other Considerations

There are a few areas that still need some thought and consideration. I’m still testing out various options for moving through and fighting over different terrain. Given the varied landscapes of Japan I don’t want this to be too much of an imposition, but certainly particularly rugged ground should impose some limitations and fordable rivers appear in a fair few battles of the period so they are important to consider too.

Defensive works is another area that needs some thought. It was quite common for armies in the period to entrench into a defensive position, especially as the ratio of guns increased in armies allowing them increased concentrations of fire. This is definitely something I want to include, either as fixed terrain pieces on the battlefield or as a “dig in” option for a unit. I need to do some more reading on this before deciding how to represent them though.

Assaulting a defensive line
Defensive works were commonly employed on the battlefields of Japan, often made from bamboo or bundles of reed mats. By the later period, concentrations of firepower would make assaulting such defensive works head-on suicidal.

Beyond that there are a number of special rules and traits I want to include. I’ve already got an outline of many of these as a means of conferring special abilities on Generals, Commanders and individual Clan units. I want to be reasonably cautious with these to avoid it becoming a bit too video gamey or “Hollywood”, but I do wish to include some means to highlight leaders who stood out from their peers through tactical or strategic brilliance, or lack thereof, as well as clans that specialised in particular types of combat or weaponry, or were particularly loyal and devoted. There’s also some consideration to be given to the numerous sects of fanatic warrior monks throughout the period and peasant rebellions. I’m not focusing too much on these until I’m completely happy with the core mechanics, though have plenty of ideas for how they could work.

Formations is another thing that needs more consideration – both the individual makeup of the sonae and how they organise themselves internally, as well as the larger formation of the entire army. For the sonae themselves, different formations may confer different sets of modifiers, for instance aggressive or defensive formations, or those focusing on concentrating firepower, while for army wide formations, I’d be inclined to leave them up to the whim of the players as if I get things right they should “just work” as they were intended given the way the battles play out. We shall see!

Beyond that I’ll want to consider some “meta” play around a campaign system, or some means of playing linked battles, as well as some strategic considerations around scouting and espionage that may aid with deployment and game set up. The idea is allow for both historical battles and ones of the players own devising covering various possible scenarios from a straight up fight, through defensive actions or taking of key objectives. I’ve not decided if I’ll look at sieges or not yet, though castle assaults were a common feature of the warfare.

Battle Report

This is one of my pencil and paper test games played out on gridded paper to try out some of these core mechanics. In it, the fictional Maru (circle) and Shikaku (square) clans engage in a clash for control of a key river crossing. I rolled for random entry points across the game area rather than having everyone come in from opposite sides, this felt natural given the mustering of troops tended to involve calling in subject clans. Each army consists of three divisions, marked 1, 2 and 3, so for the purpose of this I will refer to them as the divisions as Maru-ichi (in the south centre), Maru-ni (north centre) and Maru-san (north west), then Shikaku-ichi (west centre), Shikaku-ni (south east) and Shikaku-san (north east). The notations is as follows:

Gm = Mobile General (bonus to movement and attack, negative firing)
Ge = Encamped General (bonus to everything, messengers but no movement)
C = command sonae (bonus to everything)
X = normal sonae
F = firing focused sonae (bonus firing, negative melee)
M = melee focused sonae (bonus melee, negative shock)
S = shock focused sonae (bonus shock, negative firing)
f = fatigued
w = wavering
b = brittle

Hopefully the hills, forest, river, stream, bridge and marsh are self explanatory. The position of the number indicates facing and the negative number on commands indicate lost units.

In the opening turn the Maru-san clan attempts to skirt around the Shikaku-ichi position to link up with their General, however they soon come in range of the enemy gunners stationed on the hill.

In the south, the Maru-ichi General moves to fortify a hill opposite the Shikaku position. Meanwhile the Shikaku-ni clan rushes towards the bridge to seize the objective and support their allies. In the north the outnumbered Shikaku-san clan attempt to secure their flank on the forest and present a line of attack to funnel the Maru-ni enemy into.

The Maru-san find themselves pinned down by enemy fire as the Shikaku General brings his troops to bear on their slow advance. Feeling the pinch on their flanks the Maru-san turn to engage. In the north east, after several exchanges of fire, an impetuous rush by a Maru-ni daisho drives some of the Shikaku-san from the field, and feeling the potential for encirclement growing, the Shikaku-san pull back into a better defensive position.

Not wishing to relent on the pressure, the Maru-ni keep pressing the beleaguered Shikaku-san, while the unopposed Shikaku-ni set up a solid defence between the stream and river. Frustrated by the fire from the hill, the Maru-san charge the Shikaku General’s position. The Shikaku-ichi manage to stall them at the foot of the hill, but the Maru-ichi take advantage of the exposed southern flank of the Shikaku position and storm the hill from there.

Attacked from multiple sides the Shikaku-ichi begin to collapse and the General abandons the camp and flees for the defensive lines of the Shikaku-ni. However, the Maru-ni advance crushes the Shikaku-san in the north and begins to sweep down towards the open end of the Shikaku-ni position, while the rest of the Maru forces begin their advance towards the stream.

The Shikaku fall back over the bridge, hoping the choke point will let them wear down the enemy, but the Maru forces sweep in from all sides.

The assault on the bridge begins and while the Shikaku forces put up a brave fight, they are now heavily outnumbered by the Maru attack.
In an epic clash, the elite shock troops of the Maru-ichi break the bridge defence while the constant fire exchange across the river wears down and eventually breaks several of the Shikaku defenders. With his army broken and troops fleeing the field, the Shikaku general signals the retreat and slinks off the field in disgrace. The day has gone to the Maru, and they have secured control of a vital point between the rival lands.

This was a lot of fun as a game, the narrative flowed easily from the mechanics and while there were a few points were I had to tweak bits or come up with rules for things on the fly, it really helped me refine down some of the mechanics, and determine what did and didn’t work.


To conclude, in this post we covered:

  • Command and Control: the role of commanders and how the dynamic activation and order system works, as well as the role of messengers on the field.
  • Movement: how movement is determined and the different types of movements available.
  • Combat: both ranged and melee combat and the opposed roll system they use.
  • Morale: how units test for morale and rally from their various states of disorder.
  • Discussed other areas for expansion and thought once core mechanics are settled.
  • Finally finished with a pencil and paper test game and report on how it went.

I’m not sure what my next post on this will be, as the next stage is probably play testing and refinement, then looking at some of the special rules. No doubt you’ll see some Feudal Japanese forces creep into my painting queue in the coming year in 3mm, 6mm and/or 10mm, along with some more test game battle reports.

Thoughts and suggestions are always welcome, I’ve only been in the hobby a few years and don’t have that many games under my belt, so any pitfalls or glaring omissions I’d be interested in knowing about, so please share!

As ever, thanks for reading,


Rules for the Sengoku Jidai

The Sengoku Jidai, or the Japanese Age of Warring States, has long captured my attention and interest. The turbulent history and larger than life figures have offered prime material for any number of games, books, films, series, and more and I’ve always had an interest in the exceptionalism of Japanese history, how it rocked between long periods of insularity only to go through short bursts of seismic change. The Sengoku Jidai is one of these periods.

Brief History

Map showing some of the major clans of the era.

It is typically reckoned to have lasted around 150 years, from 1467 to 1615, and completely changed the socio-political makeup of Japan. It began with the Ōnin War, a civil war between two mighty clans under the Ashikaga Shogunate, but then spread to become a series of near constant civil war between rival clans across Japan. Powerful ancient families would fade into history and arrogant upstarts would rise to prominence only, in many cases, to fall. Famous clans like the Oda, Tokugawa, Uesugi, Takeda, Hojo, Shimazu, Date and Mori would stamp their legacy into Japan’s history as they fought for control of the provinces and country.

While Japan claims an Imperial family stretching back to the dawn of time, by this period the power of the Emperor had been reduced to that of figurehead and governance lay in the hands of the Shogun, the overall military commander of the Empire. Over the centuries, the Ashikaga clan holding this position had weakened and power became increasingly concentrated amongst the vassal clans in the provinces outside the Imperial capital of Kyoto. These clans formed a complex hierarchy or vassalage and alliance that constantly shifted throughout the period as small clans broke free of their overlords and went on to become mighty in their own right, while once powerful clans fractured to internal and external enemies.

The period ends with the Unification of Japan under the Three Unifiers: the ruthless general Oda Nobunaga who learned how to leverage European style firearms to dominate the battlefield; his successor, Toyotomi Hideyoshi, a mere peasant who rose to prominence through his craftiness and prowess on those battlefields; and finally the great politician and general Tokugawa Ieyasu, who was patient, careful, bided his time until the moment was right then struck fiercely and went on to establish the Tokugawa Shogunate, which would close off and rule over Japan until the late 19th Century.

Tokugawa Ieyasu as Shogun

Warfare in the period was also quite distinct from that found in most other historical periods and regions. Most armies were based around clan structures, and it wasn’t really until the end of the period that particular warlords, or Daimyo as they were known, were powerful enough to break up subject clan troops into larger weapon specific sub divisions. Most armies consisted of a series of mini armies, known as Sonae, each controlled by a Daimyo and consisting of a mix of different troop types. Each Daimyo would bring along their subject clans as well, so an army may consist of the top level Daimyo and the Sonae they controlled directly, then under them there could be a number of senior retainer Daimyo with their Sonae and then junior retainer Daimyo under them with their Sonae and so on. A typical Sonae would be from 300-800 men, though some powerful Daimyo could field ones upwards of 1500 men strong, or even multiple ones. As the period progressed it became more common to split off smaller units to provide specific tactical roles, for instance concentrating firepower, but in many cases battles would consist of conflicts between a series of mini armies on the field.

This was further exacerbated by the terrain of Japan, which tends towards a lot of mountains, forests and rice paddies, none of which are ideal for line up and fight battles. This meant tactical manoeuvring and flexible mixed arms units made a lot more sense than the dense pike and shot formations you’d see in the likes of Europe at the time. Battles could scale from small clan conflicts all the way up to massive battles between vast alliances of clans.

A folding panel showing the Battle of Sekigahara. Note how spread out the battle is over the hilly ground compared to how European battlefield paintings at the time appeared, with their dense formations and more gentle ground.

There’s a superb blog that goes into a lot of details on the structure of these here, but essentially I’ve been giving a lot of thought on how this would be best represented within a set of wargame rules over the past year or two.

Rule Systems

Most rules, especially those for ancient and medieval periods, assume each unit will generally have just one or two weapon types.  Those of Pike and Shot period tend to be quite specific to the European style of warfare, which doesn’t translate so well. There are some 19th Century rules that abstract mixed arms units out, but those tend to focus on the grand sweep of huge battles, which doesn’t quite fit the character of the age. I would be tempted to attempt some of the very largest battles in the period, such as Sekigahara, using this style of rules, where each unit is actually an entire division of clans, making the smallest unit a Te or division. Something like the 19th Century focused rules Bloody Big Battles could work quite well here, as would allow you to represent the different division sizes for different clan powers and there are enough modifiers to indicate tactical efficiency and concentration of firepower, with a few tweaks to the rules to handle the reduced ranges and technology available.

Guns became more prominent later in the period, often proving decisive in battle, especially on the defensive

For small scale games, many ancient and medieval rulesets will generally work well, such as To The Strongest and Hail Caesar. Within the Sonae there is an organisation of sub units based on their arms, known as Kumi, that equate pretty well to a unit of pike or spearmen, a unit of bowmen and/or gunners, some heavy infantry samurai or cavalry, etc. So for fighting battles where it is maybe a small clan vs clan battle of a few Sonae against Sonae this could translate pretty well. They did tend to fight in fairly loose order given the terrain and small numbers within the units, but that can generally be sorted out with most rule sets, which don’t concern themselves too much with specific numbers in units. There are a couple of period specific rulesets that cover this style or warfare too, Killer Katanas II and Peter Pig’s Battles in the Age of War come to mind, though I don’t yet own either.

One of the key aspects of the fighting is the use of complex formations, in which small Kumi of ranged or melee units, usually peasant troops known as Ashigaru (or “light feet”) led by a samurai, would spread out across the front and flanks probing the enemy for weaknesses. At some point there would likely be a charge of the spear troops who would fight until one side revealed a weakness and the elite samurai who would have been supporting the fighting can charge in and attempt to break the enemy. Again for a small game this works fine with many existing rule sets. You could also go smaller again down to skirmish level gaming with individual samurai and retinues, something I may consider in future as I own a Test of Honour starter set, though the rules never really inspired me to paint any of them up.

The difficulty comes from the mid size games. This is where you want the smallest unit to be a Sonae, i.e. each unit is a mixed arms mini-army of different strengths and sizes. This means it needs to be able to handle everything from a detachment of gunners up to a huge Sonae for a powerful Daimyo, without being cumbersome. The way I visualise this is each side will typically have an Army General, the most senior Daimyo, who commands the overall army, which comprises of a number of Commanders, that is the retainer Daimyo under them. Each of those Commanders is in charge of a Te, which itself is comprised of a number of Sonae, each representing the clan army (or detachment) of a more junior Daimyo.

A typical army of around 12 units may consist of the Army General’s Te, including the General themselves with their bodyguard, their own personal Sonae (usually a large size one) then a couple of smaller Sonae/detachments, then two Commanders with their own Te, each comprising the Commanders own Sonae (into which they are integrated) and 3 other Sonae/detachments representing junior clans and detachments. This can easily be scaled up and down to handle different sizes of conflict. Given the shifting natures of allegiance and betrayal, it also adds some nice potential for scenarios, or even multiple players with uncertain loyalties.

This is very appealing for smaller scale figure gaming as it allows for some very interesting basing opportunities. I’m a big fan of this blog, which discusses similar considerations and has some superb 6mm bases on show. At this point I have no figures for the time period, wanting to settle on some rules before jumping in. I’ll likely pick up some 3mm figures that can be done up reasonably generically, then use 6mm or 10mm for when I settle on what clans I’d like to work on and what scales of game I want to represent.

There are some key elements needed for a game of this type. Historical flavour being a big one, as well as the ability to try out historical tactics and the unusual formations that (allegedly) appeared on the battlefields. It should be able to handle mixed arms units in a way that is interesting and characterful. Leaders should be important. Feudal armies were intrinsically tied to their hierarchies and leaders, so they should have a strong presence on the field, while still keeping within the realms of historical possibilities. I did consider some form of duelling/challenge mechanic, but that is more something that would happen at the level of the individual combatants, not the grand tactical level of the commanders, despite what some romantic histories would have you believe!

Armies often fought in complex formations with multiple layers of attack and defence.

I’ve not come across any rules that really achieve that for me, though I may try and get my hands on BAW and KK2 at some point to see how they fare. There are some board games, Tenkatoitsu for instance, that do apparently model this somewhat and a few people have been looking at adapting this to miniature wargaming, but I’ve always had an interest in writing my own rules and this seems as good a possibility as any, so I’ve been pushing around ideas over the past while on what this sort of game would look like.

This is interesting for me as it’s making me really analyse what I do and don’t like in wargame rules to find a system that will really work for me. One thing I find I don’t overly like is extensive wound tracking. I dislike having to push a lot of dice and counters around with units when moving them, as dice are easily knocked over or mistaken for rolled dice, and when you can have more than 6 wounds you end up with multiple dice, or polyhedral dice even more prone to being knocked over.

One or two status markers is generally okay, especially if thy can be modelled to fit with the unit on the table. TtS! does this well, where most units typically only have 2 or 3 hits total, meaning you’re usually only needing to track a small number of wound tokens. I’ve taken to making one or two wound tokens with most units I make for this purpose.

I like the idea of unit status rather than strict wounds. Most modern systems are more concerned with the overall morale of a unit than specific strength reduction through damage and this is a system I favour, so my plan would be for units to have particular statuses rather than a certain number of hits.

As far as period combat goes, looking at ranged combat in the early period it was rarely decisive. Given the relatively short ranges of bows and early guns along with the looser formations of troops, ranged combat was generally not the deciding factor in battle until much later in the period where concentrated gunfire was used to devastating effect. Bows and guns were generally mixed together in varying proportions, so any ranged combat rules need to reflect the proportion of guns and bows more than differentiating the specific weapon types. Even when guns became much more prolific, they were still of primary use in defence, while offensive actions tended to favour melee. After the period, during the Invasion of Korea, the Korean and Chinese troops were more afraid of the Japanese steel than they were of the gunners who while numerous, were not considered particularly good.

As such, I want melee to be pretty decisive. Accounts seem to indicate that most melee that isn’t resolved in the initial clash can go back and forth along the line of combat until one side creates a significant breakthrough and has an opportunity to destroy the enemy. This is something I want to represent in the rules, with the standard melee phase representing the fighting between the Ashigaru spearmen, then a shock phase when one side comes out on top representing the elite samurai exploiting an advantage.

Given the nature of the clan relations, I also want something a bit more characterful with the command and control system to represent different general personalities, and to give players meaningful decisions about what to do with their generals. Typically the General would sit somewhere with a good view of the battle field surrounded by a mako screen and their bodyguards, but would also mount up with those bodyguards and charge into action when needed. I have plans to treat the general differently depending on which of these states they’re in.

The core of what make any game fun and playable is the mechanics. This is probably the key area to settle on first since the flavour tends to flow around the mechanics. There are two main parts to this, the actual means of controlling units and how they fight, them the means to hire those fights are resolved with some level of randomness. I’ll begin with the latter here.

There are, to my mind, several potential systems. One is a modified d6 system. This means for resolving pretty much any action you roll a six sided die and on a certain value it is a success. My vision for this was that the “standard” success was on a 4+ and various modifiers would move that up and down. I played a couple of test games (with pencil and paper anyway) using a system based on this and found it to be unsatisfactory. I spent a lot of time doing mental maths and mostly forgetting modifiers, so there was less of an instant “yes, it hit!” and more of a “oh I think it hit, add this, take away this, and yes…no…yes yes it hit. okay moving on…”, which doesn’t have the same impact. I also found I didn’t enjoy the act of throwing one dice over and over again.

The outcome of one of my test games. At the bottom the attacking force ground down the defender, assaulting the general’s HQ, but a relief force managed to break through the delaying force of the enemy at the top and in a daring dash, catch the exposed enemy general in the flank and drive him from the field.

I had always been somewhat put off the “bucket o’ dice” idea of gaming having seen some of the crazy numbers of dice that can be involved, but I’m actually finding that a moderate amount of dice throwing is okay, up to about the limit you can hold in one hand. There’s something much more satisfying about throwing a handful of dice than just one. My current thinking is that the mechanics consist of rolling 4 d6 as standard, then adding or removing dice (down to a minimum of 1 d6) based on situational modifiers, with success being on a 6 appearing. I don’t want to have too many of these as I want to keep things simple, but certainly things like terrain, actions and morale will play into it.

I quite like the idea of opposed rolls, where both players involved partake in the action. My current thinking is that for a shooting or melee action both sides roll their required dice and count the number of successes, then various outcomes can depend on that. E.g. in a melee if both miss then both sides pull back, if both hit the same amount, they remain locked in combat and if one sides scores more hits than the other, then things can get pretty nasty for the losing side. I’m using my trusty pencil and paper to play out some games with these mechanics to see how they fit with satisfaction, and to ensure they stay more in the cup ‘o dice than the bucket ‘o dice territory, though resolving multi unit combats is the biggest risk of buckets.

Another test game. The attacker moved in from the north west to assault the defender across a stream. The relief force attempted to join the defender but was pinned down while the attacker moved to the stream, but a fearsome defence repelled the attack and the relief force engaged with the main enemy army in a dramatic multi unit fight that broke the attackers main division. In a fit of frustration the attacking general charged the relief force commander in an attempt to drive him from the fight, but was cut down dead.

Another possibility is creating some form of Combat Results Table, where you throw, say, two dice, add them together, then compare that against a table with modifiers. I’ve seen a few quite scary examples of this, going multiple layers deep, but some systems, such as BBB, do it quite well and it’s easy to follow on a QRS. This is a potential option, but I’d quite like a system that has the immediate feedback of knowing that an action is a success without having to constantly refer to tables. I may explore the CRT in future, but for now my experiments lie more with hit dice.

I generally want to avoid “unusual” dice. That is to say d8, d10, d12, d20, etc. I have no massive objection to using them myself, but I feel they can be a barrier to entry for some people and I find tend to work better for a modified single dice system, or one with lots of complex variables. A possible exception to this is the d10, which Simon Miller very cleverly got around in To The Strongest and For King and Parliament by using a familiar deck of cards to simulate similar results. I may come round to such systems if the number of dice start getting out of control, but for now I plan to stick to standard d6.

In the next post I’ll cover some more of my ideas around the mechanics of taking actions within the game as well as a bit of a battle report of a larger pencil and paper sample game.


  • The Sengoku Jidai was a period of bloody civil war in feudal Japan.
  • The terrain and complex clan hierarchy meant armies were more retinues of retinues than strictly organised armies.
  • Each unit in the army may be a mini army unto itself with mixed arms.
  • Most rulesets deal with the actions of small armies and their constituent parts rather than these mixed units.
  • I’m having a go at developing my own rules to cover this.
  • Having toyed with a few types of resolution mechanics I’ve had some success with a dice system somewhere between a single modified dice and a large bucket of dice.
  • Next time a little more on the action mechanics for movement, combat, etc, and a battle report.

Thanks for reading,