Large-scale battles are sometimes a useful way for GM to put players in the middle of forces much larger than themselves. It drags them out of the "small, ragtag band of murder-hobos rampaging through a dungeon" mindset, and puts them in the middle of a conflict that they probably can't solve by simply rolling dice and hitting things. It also forces politics into the story (since the two sides are fighting for a reason, right?), which can add a very different theme to a campaign, if you want a break from the never-ending combat encounters.
Large-scale battles are an abstract system where armies fight against each other. The PCs are not on this board. Instead, they engage in encounters, skill challenges, and other types of 'traditional' encounters during each Engagement of the large-scale battle, in the hopes that their own actions can influence the outcome of the battle in their favor. For example, while the first Engagement of the battle is going on, the players may choose to perform an 'intercept orders' action, where they intercept the marching orders of two of the enemy's units and replace them with orders of their own. This is resolved as a traditional combat encounter, except that the primary objective of the players is the kill the courier and steal his message (replacing it with a forgery of their own), before enemy reinforcements can arrive. The players will fight the courier's guards, but after the 3rd round, a lot more guards will arrive, making success for the mission impossible. If the players don't succeed by the end of the third round, their mission fails and they are forced to retreat. If they succeed, however, they may swap the placement of two of the enemy's units on the enemy's side of the battlefield before the start of the next large-scale battle Engagement. After that, win or lose, the players move on to their next effort to either bolster their own forces' strengths, or undermine the enemy's strengths.
Of course, the enemy might have a commander or band of their own heroes, who can engage in similar operations. The players might not even know such a group is acting until strange things start happening on the battlefield (such as two of their own units getting swapped around). This could all lead up to a final battle between the PCs and the enemy champions, just as the battle itself is reaching its own climax. Fun times!
Also see Timescales for more information.
Large-scale battles are never held in the same tactical battlefield (or battle mat) that players use to fight their own encounters. It is played on a grander scale, where each square of the map represents a space large enough to hold a unit of 1,000 troops. This secondary board is referred to as the 'battle space', or the 'chessboard'.
The Chessboard is frequently a standard 8x8 chessboard (or checkers board, if that's how you roll). Smaller battles can take place on a board that is only 6x6, or even 4x4, while larger battles can take place on a 10x10 or a 12x12, if necessary. The chessboard should always be an even number of squares on a side, and should always be a square. This allows the deployment areas to be equal in size without leaving a 'no man's land' in the middle, as an odd-numbered size would create.
Each side in the battle can set up their troops on their half of the board of their side, taking turns to place each unit. This is called the 'deployment area'. If any side of the battle ever has more units than squares available on the board, they must hold any remaining units in reserve (off the board) until room is freed up for those units to enter the battle. Reserve units must move into the battle from the back row of their side (they cannot enter from the sides or from any squares in the enemy's deployment area), unless they possess some special ability that changes their deployment rules (such as cavalry).
Most medieval battles were fought in open plains because they granted no advantage to either side, and both sides would maneuver to force the engagement in such an area. Battles in forests were truly uncertain things where unit cohesion was nearly impossible, and the advantage of charging units, like cavalry, was almost entirely negated.
However, some battles were fought at river crossings, or near keeps, or castles. Such battlefields were not simple, open plains, but instead contained terrain features. Fantasy battles might be fought on terrain that one side feels is advantageous, while the other side can only desperately adapt, such as an army of fire elementals on the side of a volcano facing off against a human empire.
The GM may add some difficult terrain, blocked terrain, hazardous terrain, or points of interest to a battlefield, if they wish. In a case where players are in control of an army, and they can dictate the location of a battle, GMs may wish to allocate players a certain amount of terrain that they can place before the deployment phase. Caution is advised, especially for the first few battles in a campaign, as players (and GMs) may wish for a few simple battles to learn the rules and strategies on offer by this system.
If terrain features are used, the number of blocked or difficult terrain spaces MUST be equal on both deployment zones (both sides) of the chessboard. That is, if one side has 3 blocked spaces, the other side must also have 3 blocked spaces. They do NOT need to be mirror-images of each other; they could be nicely out of the way on one side, and heinously inconvenient on the other, but they MUST be present and equal. GMs are encouraged to be creative, but at least slightly fair with terrain features. Remember that squares in this battlefield are often a few acres in size each, and therefore, features like difficult terrain should be due to very large terrain features. On the chessboard, a mighty river may only be a single square wide, for example, where on a traditional battlemat it would occupy the whole table. Something small, like a house, would not even inconvenience the movement of a unit, and should therefore not be designated on the chessboard.
Note that major defensive features, such as a castle's walls, or even a city's walls, are often not the 'center' of a battlefield. Usually, features such as these aren't on the battlefield at all. The attacking army would usually line up beyond the reach of archers on these battlements, and either wait to be engaged by an army sallying forth from the castle or city gates, or would siege the location until the populace starved enough to surrender. Such longer-term sieges would sometimes also employ sappers to tunnel under the walls (compromising their foundations), or use siege weapons to break them, well before any real engagement of armies took place. Consequently, no sensible army would ever choose to fight a fully-intact city or castle wall, with a fully-healthy defending force. If a GM wants to run a battle on a castle wall, the wall should start out compromised, or the defending force should be VERY depleted due to starvation and rioting (and disloyal) peasants. A GM should NEVER begin a battle is bisected by a wall unless the attacking army genuinely has no choice but to attack, or they have some means of easily overcoming the defense (e.g., they can all fly, or they have a unit of dragons).
Military units, when they are fully mustered and healthy, consist of approximately 1,000 troops. They have a small set of stats, like monsters, but their combat mechanics are MUCH simpler. All units have the following stats:
- Attack (red chips)
- Defense (white chips)
- Movement (blue chips)
A unit's attack stat represents its expertise with its weapon. A unit's defense stat represents how well it can withstand the brutality of battle. A unit's movement stat represents how quickly it can move around a battlefield. In many cases, these numbers are quite low, and without a special ability, don't offer much utility. Some units inflict more damage if their ATK value is greater than a defending unit's DEF value, but in the absence of an ability like this, defense values are basically just more hit points for the unit.
Furthermore, the combined value of these three stats represent the unit's current (and total) health. As a unit takes damage, it reduces one of its three primary stats by the damage amount. If any of the unit's primary stats are ever reduced to zero, the unit becomes 'routed', replacing all of its stats with just "movement 2" (which consequently alters its remaining hit points to just 2, regardless of what remaining stats it might otherwise have had). For example, the weakest unit in the game, militia, which are just farmers and townsfolk with no training, and probably only the equipment they could scavenge from their own attics, have 1's in each of their primary stats: Attack 1, Defense 1, Movement 1. If they take any damage at all, they will become 'routed'.
For simplicity's sake, it can be very helpful to represent each unit on the field as a stack of colored chips, with each color representing one of the primary stats, and the quantity of chips of that color representing its value. Alternatively, you can use small squares of cardstock or paper, and write their primary stat values on them, and just update the numbers as the unit takes damage. You can even use d6's for each of the stats, but that can get a bit fiddly. We have found that a stack of colored chips is the easiest to work with, and it makes it easy for all parties to see how strong each unit is, on the board. Poker chips (or any other kind of stackable chips with at least 3 different colors) work well. Ideally, you'll want between 100 and 400 of each color, and picking colors that contrast easily against each other (and aren't opposites, for those of us who are color-blind) is recommended. These rules suggest red for attack, white for defense, and blue for movement, but you should feel free to use whatever colors you have available and are easily distinguishable from each other.
If the players have any say over how their side is deployed in the battle (i.e., they are participating in the strategy meetings with the generals for their side, or some similar level of social engagement with the leadership of their side), there is a deployment phase. If the players are not involved in the strategic planning of the battle, the GM may set up both sides of the battle instead, skipping the deployment phase. (In these cases, GMs should always deploy both sides 'fairly', such that no side is deliberately harmed by bad deployment, unless there is some story reason why that would be the case.)
During the deployment phase, each side takes turns placing a single unit in their deployment area of the battlefield, beginning with the defender, until all units are deployed, or are declared to be 'reserves'. Declaring a unit as a 'reserve' counts as a turn for deployment.
When units are deployed, their stats and special abilities are exposed and become 'known information' to both sides of the battle.
Either side may also choose to declare that one or more of their units is being held "in reserve", in which case, they do not need to deploy them, and they also do not need to reveal their stats or abilities.
A unit that has been held in reserve can be deployed during any engagement round, but must move into the battlefield from the controlling player's back row, unless the unit has some special ability that can break this rule. As soon as a reserve unit is deployed, its stats and abilities are revealed for all to see.
A single engagement round consists of each unit on the battlefield (and optionally one, some, or all of the reserved units) moving and attacking once each. This is accomplished by taking turns, beginning with the defending side, where each side moves one of their units (if they wish) and then attacks with it, and then the next side goes. This continues until each unit has moved and attacked once. No unit may move and/or attack more than once per engagement round.
Once a unit has moved and attacked, it should be marked in some way to clearly indicate that it has already acted this Engagement Round.
Moving a Unit
A unit may move a number of squares on the battlefield equal to its current Movement (MV) value. If it has suffered any damage that has reduced its Movement value from its starting value, it may only use this reduced value, not its starting value.
Movement is always optional. If a unit prefers not to move, it doesn't need to move.
Movement can be in any of the eight directions available on a square grid: forward, backward, left, right, or diagonal. Diagonal movement does not cost extra. Units may not move into squares occupied by other units, but they can move through allied units if they can end their move in an unoccupied space.
Special: A unit may expend 2 squares of movement to swap places with an allied unit.
Special: A unit may declare that it is giving up its attack action for the round to allow it to move 1 square, even if the square they are moving into is difficult, or even impeded, terrain. This special cannot be used to end the unit's movement in a space that is already occupied by another unit (whether allied or enemy), nor can it be used to move into a blocked space.
Combat in this system is very simple, and deterministic. No dice are rolled to resolve large-scale battles. Instead, if one force has a numerical advantage against another, it is almost a foregone conclusion that it will eventually overwhelm the opposing side, given enough time, and no interference by some pesky adventurers. And this is the whole point. The heroes are essential to the outcome of the battle, even though they are not directly participating on the battlefield.
When a unit completes its movement (or decides it isn't going to move), it can then choose an enemy unit within its reach to attack. Most units have a reach of 1 square (though some units, like archers, can attack creatures out to 2 squares away).
The attack is resolved quite simply: review the attacking and defending units' special abilities. If neither unit has an ability that alters the way basic attacks are resolved, the attacker inflicts a point of damage on the defender. That's it.
Some units have special abilities that add some complexity to this. For example, the "skirmisher" ability allows infantry units to deal an extra point of damage to a unit they attack, if their Attack (ATK) value is greater than the defending unit's Defense (DEF) value.
Recall that a unit's "hit points" are equal to the sum of its stats: Attack (ATK), Defense (DEF), and Movement (MV). Consequently, when a unit takes one or more points of damage, it results in the reduction in one or more of these stats.
The side that is controlling the unit that took the damage gets to decide how the damage is removed from the damaged unit (i.e., the defender gets to choose how its damaged unit gets reduced).
To apply damage to the unit, simply declare which of its stats is being damaged, and reduce that stat by the damage amount. If more than one damage was dealt, the defender may split the damage among more than one stat on that unit to 'spread around' the damage, unless the attacking unit has some special ability that breaks this rule. In this way, most units suffer damage until all of their stats are reduced to 1 each, before any one stat is reduced to zero.
If any one of the unit's stats is reduced to zero by damage, that unit becomes "routed" (see below). A routed unit loses all of its remaining stats, and replaces them with only a "MV 2" stat, giving it two points of movement only. This means that unit can no longer attack, and if it suffers two more points of damage after this point, it is "destroyed" (see below).
Note that, for a unit to become routed, one of its stats must be reduced to zero. If a unit begins with a value of 0 in one of its stats, it is not automatically routed. A unit can only become routed if it suffers damage that causes one (or more) of its stats to be reduced to zero.
If a unit takes multiple points of damage, and some of that damage causes one of their stats to be reduced to zero, all remaining damage from that attack is ignored when they first become "routed". This means it is impossible to do so much damage to a unit that it goes from "not routed" to "destroyed" with a single attack. Subsequent attacks made against the routed unit, on the other hand, are resolved against its new "routed" stats (i.e. its 2 points of Movement).
Routed units can still move anywhere the controlling player wants them to move, as long as they have sufficient remaining movement points to do so, and the spaces they wish to move into are legal spaces.
Historically speaking, when a unit is "decimated", it has lost 10% of its fighting power. A "routed" unit essentially decimated, and has therefore suffered enough morale loss that it is no longer willing to fight. It is still loyal to its side, however, and may elect to move into locations that are strategically advantageous to their side, despite the fact that the unit can only really serve as a meat shield at this point. Sometimes just getting in the way can be vitally important to the battle's outcome.
However, cautious players may wish to move routed units off the battlefield as quickly as possible to prevent them from becoming destroyed.
If a routed unit's Movement stat is reduced to 0, it becomes "destroyed". A destroyed unit is removed from the battlefield, since it has suffered so many casualties that it no longer behaves as a "unit", and is instead, just a bunch of panicked creatures thinking only of their own personal survival.
As you can see, the large-scale battle system is fairly straightforward. Almost boring in its simplicity. It is the actions of the player characters that turn all this into something fun and interesting.
Between each Engagement Round, players choose a mission to go on, in support of their side's forces. Most often, these missions are efforts to disrupt or reduce the enemy's effectiveness, but it can also be a mission to provide support and relief to the allied troops, if the player characters favor taking more humanitarian actions.
Usually, there is an opportunity for the players to perform one mission after the Deployment Phase, but before the first Engagement Round, unless the players were not aware the battle was going to occur (i.e. the enemy army somehow managed to gain the element of surprise). In such a case, the players can't perform a mission until after the first Engagement Round is finished. However, players can always perform a mission between each subsequent turn, until one side or the other is defeated.
The following is a list of possible actions the players could engage in, between Engagement Rounds. This is not meant to be a comprehensive or complete list; GMs are encouraged to invent their own that are relevant to the battle being fought. Furthermore, it is often a good idea to present the players with around 3 options to choose from, where they can only accomplish one. Cruel GMs might even examine the two missions the players chose NOT to do, and elect to have some minor consequences for having ignored them (these consequences should never outweigh the benefit of having done the one they picked, of course; the goal is to make the players feel like they are critical to the success or failure of the battle, not to punish them for 'wrong' choices.)
Intercept Enemy Orders
- kill courier (who is surrounded by 1 encounter's worth of guards)
- someone must spend a standard action performing a sleight of hand check (or other roll, as allowed by the GM) to swap the pouches
- another full encounter's worth of bad guys will appear at the bottom of EVERY round, beginning at the bottom of round 1.
- the players must escape off one of the edges of the battle mat to be victorious.
- On Success:
- Players may choose two of the enemy units prior to the start of the next Engagement Round, and swap their locations, as they receive the wrong orders.
Disrupt Supply Lines
- disable at least half of the wagons, and then get away (off the edge of the map)
- there are two wagons per PC, and two guards per wagon
- guards are equipped with crossbows (fire every other round), and can also get off the wagon as a standard action
- disable at least half of the wagons, and then get away (off the edge of the map)
- On Success:
- Players cause one point of siege damage to the enemy force, plus one additional point per 2 additional wagons they destroy (i.e. 2 points at 3 wagons, 3 points at 5 wagons, etc.), as starvation sets in. The GM gets to decide which units suffer this damage, and can spread it around as they wish, but they must allocate all of the damage somewhere.
- Sneak into the enemy camp (skill challenge for stealth)
- Attack an above-CR encounter's worth of bad guys, of the same type as whatever unit they are trying to weaken
- Players can declare the battle is over at any time; they simply leave the tent or small camp to 'leave' (much smaller map than the others)
- On Success:
- Players inflict a number of points of siege damage to that enemy unit equal to the number of creatures they kill in the encounter.
- Kill the enemy general (a leader role)
- Leader is surrounded by a double-encounter's worth of bad guys.
- On Success:
- Choose up to three routed enemy units. You may move them however you wish, including off the board, as long as the move is legal. These units are treated as if they have already acted, during the upcoming Engagement Round (i.e. this movement counts as their turn for the round).
Victory or Defeat
- All units on one side are either routed or destroyed
- One side has a 2:1 advantage over the other side, counting only non-routed, non-destroyed units.
- Some other special condition: maintain control of one space on the board for at least 3 rounds, get a unit to the far side of the battlefield without it becoming routed, etc.
Unit Special Abilities
Advanced units often have a special ability, in addition to their primary stats. It is exceedingly rare for any unit to have more than one special ability (like, basically never). Some examples of special abilities include:
- Ranged -- This unit can attack a unit that is 2 squares away, but cannot attack adjacent units.
- Cavalry Charge -- Cavalry units are always reserves (they start off of the board when the battle lines are drawn up. Unlike normal reserve units, they can enter the board by moving in from any edge (including the enemy's back edge), but they must move in a straight line, and attack the unit at the end of that straight line. They always have enough move to get to the unit directly in front of them for this charge. Once on the board, the are treated like any other unit (i.e., this is a once-per-battle ability).
- Skirmisher -- If this unit's ATK value is greater than its target's DEF value, it inflicts 2 points of damage, instead of just one.
- Lesser Flight -- treats all terrain types as one step lower: difficult becomes normal, impeded becomes difficult, and blocked becomes impeded.
- Greater Flight -- can ignore all movement penalties associated with difficult terrain, and can move through any terrain. Cannot stop in a blocked space.
- Magic -- magic damage always bypasses defense, meaning it always inflicts damage, even if the defender's Defense stat is extremely high.
- Area -- some attacks can hit more than one square, attempting to deal damage to all units in the affected area. However, this damage is always indiscriminate -- it will hurt friendly units, too.
- Siege -- siege damage targets terrain, in addition to the unit in the target square. If an impeded or blocked space is hit with Siege damage, it is reduced by one step (to difficult, or impeded, respectively). If a normal terrain space is hit by Siege damage, it becomes difficult terrain. Siege damage doesn't change difficult terrain.
- Shield Wall -- +2 defense versus melee attacks from enemies directly in front of this unit (diagonal attacks, flanking, and rear attacks go against normal defense number).
- Turtle Formation -- +1 defense versus ranged attacks.