Thursday, 15 December 2022

On rules for committing reserves

I am fresh from an epic game in which commitment of reserves was crucial. Maintaining a reserve is a rather fundamental principle (even if it doesn't make it into the UK military's list of 10 principles of war these days). Any real-life general will keep troops in reserve: to exploit success in the attack; to plug holes and counter-attack if defending; and generally to respond to unexpected or adverse events. This is mainly because of fog of war, something which our tabletop games don't do very well. We wargamers with our helicopter view usually know how many troops our opponent has, where they are and what they are trying to do. It is hard to achieve deception and surprise, so there is not as much incentive as in the real world to hold troops back just in case.

Some rulesets make an effort to address this by various means. Units that are formally designated as reserves may enjoy certain advantages in exchange for initial restrictions. Units beyond a certain distance from the enemy might qualify. Command point systems or card-driven mechanisms might reward players who keep a reserve.

"Bloody Big Battles!" (BBB) makes no special provision for reserves in the rules as such. However, BBB relies on historical scenarios, and a number of the published scenarios do specifically deal with reserves in different ways. I list a few of these below, but first let me talk about the game that provided this talking point.

The Chernaya (1855) was the biggest battle of the Crimean War. In November the guys played it while I was away - see their composite report here. They had such a good time that Crispin decided to run it again (plus he'd put a lot of effort into making the custom terrain). He and I got to be the Russians against Dave and Mark as the Allies. Victory or defeat hinges on how long it takes the Russians to commit their reserves - more than half their army. The scenario stipulates that the reserves are not released until a Russian unit has crossed the Aqueduct (the line the Allies are defending) and held off any Allied counterattack in the following turn.

We had to fight this one and a half times on Monday evening. Our first attempt was abortive: every Russian attempt at crossing the Aqueduct was either repelled by deadly Allied fire or driven back again before it could establish a foothold. After four turns of failure we accepted defeat, reset, and tried again with a slightly different plan. It was still touch and go, but by the skin of its teeth one Russian brigade clung on on the far side and the Russian hordes were unleashed. After that there was still plenty of furious fighting to be done, but we were eventually able to report a victory to the Tsar, albeit with a horrendous casualty list.

Looking south from behind the formidable Russian reserves (infantry lower left, artillery lower right). The substantial Russian cavalry reserve is out of shot to the left. The River Chernaya and the Aqueduct snake across the middle of the table. The infantry columns of the Russian advance guard are pushing across into the teeth of intense fire from the French line at the foot of the Fedoukine heights (four white objective markers indicate N, S, E and W Fedoukine). French reserves mostly came down from the Sapoune Ridge (top right). Sardinians out of shot guard the French right flank.

It is hard to overstate just how tense and dramatic those turns 2-4 were, while we were desperately trying to cross the Aqueduct and the French were trying equally desperately to thwart us. This 'trigger condition' for releasing reserves lent real urgency to the early moves and made every assault seem crucial and exciting.

Added spice was provided by the Allies' decisions over their own reserves. They have several French divisions available, including the Imperial Guard, as well as the British cavalry division. They may commit as many of these as they wish, at any time - but the more they commit, the greater the risk that this will cost them victory points (representing bad press back home about how serious the Russian attack was and/or how nervous the Allied generals were). This alone meant they had important decisions to make virtually every turn.

This game was truly epic and memorable, and the way the scenario handles reserves had a lot to do with it. This one scenario offers two different approaches. I have surveyed the available BBB scenarios and identified a few other possible ones. We might categorise the various options as follows. I have tried to group them into related types ('Take what you're given', 'Earning it', 'Preventing it', 'Paying for it'):

Take what you're given (simple basic approaches, no choices for players to make)

1. No restrictions. All troops on table, players may commit any and all as soon as they like.

2. Scheduled reinforcements. Frequently, BBB scenarios provide for troops to arrive during the course of a battle at around the time and place where they did historically. The players typically have some latitude over the arrival points for their reinforcements, but no influence over when they arrive, e.g.: 'Arrive Turn 3 within 12" of SW corner".

3. Scheduled release. Commonly a scenario states that certain units may not move on the initial few turns and specifies a turn when they will be released for use. This is a simple way to reflect the fog of war and limited information that usually prevents a real general from going 'all in' on Turn 1. Published BBB examples include the French at Gravelotte (1870), Beaumont (1870), or Sedan (1870); likewise the Italians at Custoza (1866) or the Russians at Metschka-Tristenik (1877), among many others.

Earning it (players' success or otherwise during the game affects what reserves they receive)

4. Triggered release. Similar to the Russians at the Chernaya, in the BBB scenarios for the Second and Third Battles of Plevna (1877) Russian reinforcements are triggered by the Russians capturing certain Turkish redoubts. This represents the decision to reinforce success. Pered (1849) also has such a 'triggering condition'. The Hungarians need to capture at least 3 objectives on Day 1 to be able to commit a reserve corps on Day 2, otherwise it has to wait until Day 3. In a draft scenario for Antietam (1862) I tried a trigger condition for releasing Porter's V Corps. 

5. Wrestling for advantage. Nagy-Salló (1849) is effectively an encounter battle in which the majority of both sides' troops arrive as reinforcements, subject to die rolls. The trick is that whichever side holds the central objective (the village of Nagy-Salló itself) is deemed to be accordingly more confident, so gets a +1 on its dice for committing reserves. This is the only scenario in which I have used this device, but it works so well I think it deserves to be used again.

Preventing it (players' success can stop enemy reserves being released)

6.  Deterrence. Montebello (1859) takes the choice out of the owning player's hands but lets his opponent influence it. The outnumbered French are trying to make themselves look bigger than they are by acting aggressively. An Austrian reinforcement unit arrives every turn unless a French charged on the previous turn. This represents the Austrian commander's caution in the face of French counter-attacks. It's a rather specific situation, but this is certainly a successful way of recreating it.

Paying for it (players can choose to commit reserves but risk paying a price of some kind if they do)

7. Victory point gamble. This includes the Allies at the Chernaya, trying to calculate whether the chance of retaking a lost objective is worth the risk of losing a victory point by committing the reserves to do so. Balaclava (1854) is similar to The Chernaya in that both sides risk sacrificing victory points if they choose to commit reserves. Sepsi-Szent-György (1849) offers another variation on this: the Hungarians have the option mid-game of committing additional forces - but if they do, their victory conditions also get harder. The fact that they have that option obliges their Austrian opponents to keep back some reserves themselves to guard against that possible additional force.

8. Schwechat (1848) is an interesting one. The Austrians are defending against a Hungarian army that is marching to aid the besieged revolutionaries. Turn by turn, the Austrians may commit reserves from their besieging force to help to fend off the Hungarians. However, the Hungarians have a one-time die roll to see if the Viennese will sortie against the Austrian rear - and the more Austrian reserves have been committed, the higher the chance of a sortie.

This is by no means an exhaustive list. There are undoubtedly many other ways of representing reserves: formal orders statuses, card activation systems, command point systems ... rather than try to list them myself, let me invite you, my loyal readers, to comment on what approaches you have seen used in wargames rules, and which you like and why.

This short essay is one of a series of 'Reflections on Wargaming'. If you'd like to read more such pontifications, see the full list here.


Update added 18 December 2022


This essay was deliberately only half-written originally. I expected lots of feedback and I was not disappointed: dozens of you wrote thoughtful and considered responses on TMP, Pendraken and TWW. These deserve some review and commentary from me in return.

The responses I received fell into these broad categories:

What do you mean?

It was pointed out that I blurred the distinction between ‘reserves’ and ‘reinforcements’. Of course reinforcements may arrive and then be held in reserve, while reserves may be used to reinforce an attack or a defensive position. I hope that clarifies things.


I don’t see the problem

A number of respondents took the view that players should be entirely free to order all their troops around as they saw fit. I can see the case for that – in fact, my Chernaya scenario that prompted this post provides exactly that as a scenario option.


But let’s consider an obvious example I should have included to start with, namely Napoleon’s Imperial Guard. Napoleon usually saved these up until late in a battle, yet any wargamer worth his salt is likely to try to get maximum use out of his best troops. Do we think Napoleon was always doing it wrong? The BBB Waterloo scenario awards the Allies a victory point if the Guard infantry are spent or destroyed. That leaves the player the freedom to commit the Guard, but with a penalty if he loses them. Is that still too restrictive?


Also I will maintain that sometimes tying players’ hands a little initially is a suitable way to compensate for their perfect information and the absence of the uncertainty or ignorance or even deception that the generals suffered from on the day. I don’t want to straitjacket players and force them to repeat their historical counterparts’ plans and mistakes, but I do want them to face similar historical constraints so they can appreciate the historical problem.


Greater freedom of movement for reserves

I quite like Andy O’Neill’s simple summary: ‘Committed troops – you already gave them a mission. Wave goodbye. They’re out of your control. Reserves. You may give them a mission. Until you commit them to some action. Then, see above.’ It’s not entirely applicable to games of the scope of BBB that can encompass several days of battle, but it’s a fair point that reserves may be easier to move around the battlefield than troops that are already engaged. Readers offered various mechanisms to reflect this: shorter time to activate orders changes, double moves or longer movement distances, a +1 on activation rolls … ‘Daft interpenetration rules’ were mentioned as a problem deterring players from holding units in reserve. ‘Order, counter-order, disorder’ was given as a factor that doesn’t get enough weight in a lot of games.


Morale benefit of reserves

It was suggested that the presence of nearby reserves could/should help units to pass morale checks.


Fast-moving games encourage appropriate use of reserves

Readers noted that games that do not last enough turns and/or have large enough movement distances for troops to move far across the table encourage players to put everything in the front line early. By contrast, games with room for maneuver and with movement distances large enough to significantly change the situation quickly allow more unpredictability (necessitating reserves) and the opportunity to react (making reserves appropriately worthwhile). Steve Holmes used the phrase ‘zooming out’, i.e., the advantage of starting the game not when two battlelines are about to clash, but before they are formed, thus allowing for more approach maneuver, which also brings reserves, flank marches etc more into play. Phil Dutré rightly raised troop density – wall-to-wall troops don’t leave much room for maneuver, nor for unpredictability (though I suppose they might force creation of a second line aka reserve if there isn’t room for everyone in the first line!).


Similar but different, the game dynamics need to make it possible for a series of attacks and counter-attacks to happen during the course of a game, contra Murvihill’s complaint: ‘Most games I’ve played only have time for one attack before the game is over’.


I would say BBB meets these criteria – as Vincent Tsao’s review here reports, ‘Movement is generous […] A unit can cover a lot of ground if it is unopposed’. Activation rolls mean reaction is not guaranteed, so a prudent player needs to anticipate as well. Scenarios are often ‘zoomed out’ deliberately so as to allow time and space for maneuver. And as anyone who follows this blog will have seen, a typical BBB game will rarely be a simple story of a single attack. Instead, there is ebb and flow, thrust and counter-thrust, the tale will twist and turn a few times before it reaches its end.


Army break points militate against retaining reserves

Some noted that certain rule systems that use ‘army break point’ to determine victory reward players who put everything up front rather than retaining a reserve.


Who should have control?

There was discussion about whether it is both more realistic and more fun to have arrival/availability of reinforcements/reserves essentially random – at the whim of fate (aka higher command) rather than the player having any say.


Do game mechanics adequately reflect fatigue etc?

It was noted that rules need to give sufficient advantage to fresh troops vs spent ones, and to reflect gradual exhaustion and increasing disorder and attrition. Even if casualties are negligible, or even if not directly under fire most of the time, simply standing to for hours in sight of the enemy is physically and mentally draining.


One of Clausewitz’s most interesting quotes, in my view, is this: ‘Delayed commitment of reserves – or outflanking through time, to put it another way – is always a very effective principle in modern warfare.’ (Carl von Clausewitz, ed & transl Murray & Pringle, ‘Napoleon Absent,Coalition Ascendant: The 1799 Campaign in Italy and Switzerland, Vol.1’, p177.)


Time spent in reconnaissance is seldom wasted

John Salt observed how rarely this venerable military maxim figures on the wargames table. This brings us back to the fog of war aspect I raised at the start of this post. Rules or scenarios where reconnaissance to identify enemy strengths, locations and intentions plays a significant part are also more likely to see players husbanding reserves until they have a clear enough picture to commit them.


Rules that represent reserves well

The Blücher, Rommel, Chain of Command, and Sharp Practice rules got honourable mentions for how they treated the ‘greater freedom of movement’ or ‘fatigue and attrition’ respects.



Let me summarise, then. First, let me state that my games, and I assume yours too, are trying to achieve at least two relevant goals:

- To present players with a challenge in the form of either a historical situation as faced by a historical general, or at least a plausible one with some foundation in history;

- To provide an entertaining game.


Uncertainty and unpredictability are key elements for both goals. Historical generals always had to deal with unknowns, and good wargames also need to provide us with surprises.


Surprises can be generated by game mechanisms that have some random element and whose time-space relationships make it possible for dramatic maneuver to change the situation significantly in a turn or two. Such game mechanisms encourage appropriate use of reserves. There are many ways to do this. I believe BBB does a good job in this department.


Historical surprises or uncertainties can be represented by scenario-specific rules that put suitable constraints on players. It is by no means always necessary, but BBB scenarios demonstrate that there are many different ways to do this if required. The Chernaya scenario as reported above is a prime example of how this can generate a uniquely exciting game.


Let’s finish with another quote: “There are known knowns, things we know that we know; and there are known unknowns, things that we know we don't know. But there are also unknown unknowns, things we do not know we don't know.” ― Donald Rumsfeld, Known and Unknown


  1. Something I've seen in other rules is allowing reserve units to make a double move on the turn they are committed. TFL WWII rules Chain of Command (platoo level) have reserve units arrive at specified on table locations. Those who don't like it say they are 'teleported'. I rather like it.

  2. As always Chris an interesting and thought provoking post. For big historical battles such as the ones covered by BBB, I think the above options cover things nicely.

    For general games at a smaller level such as those covered by Honours of War or Warlord Games Black Powder II et al, that you would typically see played at a club or at home, then I can't think of anything that covers reserves per se. Units a certain distance away from the enemy might be able to double move, but that's about it.

    However I think any gamers playing 18thC - 19thC games would be wise to maintain a reserve for the reasons you have stated. I know this works particularly well for HoW & BPII, both are games which I enjoy. If you don't then things can unravel rather quickly.

    We also try to avoid the God's Eye view we have and try to manouevre according to the terrain and what we could reasonably see, despite of course knowing what is the other side of the hill! This makes for a much better game IMHO.


Comments welcome!