While writing the Manslayers and now the Bloody Hands war camps, we quickly realized that managing 100-200 NPCs is really hard and that GMs were going to need explicit advice on how to keep up with it all if we were going to expect most of them to be able to run encounters like the Manslayers Camp as something entertaining rather than as a hot mess.
Several of the encounters in this hexcrawl are war camps, a collection of 100+ monsters all gathered in one area, where they live and work. Since there’s a huge number of them, they all have routines, and players can arrive at any time, the camp can be in any of three or four different configurations and many of these configurations are very hard to keep track of without the right preparation.
Here’s how to make it easy. Divide the camp into different sections (usually some guidance for this will have been provided in the war camp’s write-up). Then divide the forces of the camp into groups of about 5-15 creatures a piece. These groups tend to stick together, and will only split up or recombine under unusual circumstances.
Think of each section as a single space on the battlemap, and each group of 5-15 creatures as one unit. By taking a dash action, each group can move to a neighboring section. For every 30 feet their move speed exceeds thirty, they can move one additional section when dashing (so, 60 ft. is two sections, 90 feet is three, and so on). They will arrive at the end of the initiative count for the current round if you are in combat time, and will roll initiative for the next round and act as normal. If they’re patrolling at regular pace and not running to provide reinforcement, then it takes 3 rounds to reach a new section. At the end of initiative every third round, all those patrolling at a regular pace move one section. Creatures with a speed of at least 45 take only two rounds, and creatures with a speed of at least 90 can move one section per round even when patrolling. A creature with 180 foot speed, if such a thing even exists, can patrol through two sections in one round.
This will reduce a war camp of two hundred individual units down to about twenty and that cut the prep time for keeping track of who’s out of the camp, who’s guarding a specific section of camp, who’s patrolling and where, and who’s asleep much easier. Almost all enemies in a camp can be divided into one of those four behaviors, and each of them will respond to an alarm differently.
Enemies who are outside of the camp, usually foraging or on patrol, are called hex patrols, and will stick together into their groups but will usually be far out of sight from other groups. When players out in the middle of a hex have a random encounter with a group of enemies from the war camp, this is who they’re encountering, and hex patrols will not ever arrive as reinforcements during a fight in the main camp unless it somehow drags on for hours (hex patrols who do return to find intruders in the camp will stick around to kill them, and enemy groups in the camp are normally scheduled to go on hex patrol, they won’t if there are intruders). Players can also stalk these groups until they’re a good far distance away from the camp and then fight them alone. These individual groups are rarely trivial encounters, but they are quite manageable, as opposed to the vast numbers contained in the main camp.
The days after one hex patrol goes missing, other hex patrols will be less likely to fight unknown opposition (or especially opposition known to be responsible for killing the other patrol), although aggressive creatures like orcs might seek glory bringing down the threat anyway. After two or three hex patrols go missing, the camp’s commander will almost always order that hex patrols remain behind and guard whatever section of camp they live at instead of continuing to patrol outside the camp.
Enemies guarding a specific section of camp are called guards and will guard a specific section of the camp and will not leave that section of camp, even if there’s fighting going on elsewhere, unless the leader of the camp sends orders to move to another section of the camp. Being reassigned to another section of camp will usually happen for one of two reasons, either one section of camp has had most or all of its guards destroyed and the leader reassigns guards there to fill in holes in the defense, or else the camp has been so depopulated of guards in general that the leader is recalling all remaining guards to the most vital areas of the camp, usually the leader’s own section of it. The leader of a war camp may reassign guards for either purpose during an ongoing battle in the war camp, but remember that in order to do so the leader must first be informed of the situation by a runner, then send a runner to the guard units he wants to reassign, and then the guard units must move to the designated area. Each of these is an independent group taking independent moves, so it may be several rounds before guards move to reinforce a section of the camp even if they’re adjacent to it.
Enemies who patrol around the camp are called camp patrols, and they move around the camp looking for intruders. If they hear the sounds of combat, then they will immediately move to engage the intruders without waiting for any orders. Camp patrols are much scarier for players, so you might wonder why anyone is ever ordered to guard instead of patrol. The answer is that diversions are a thing, and indeed the players may even attempt to cause one in order to draw all camp patrols to a section of the war camp opposite of their real goal. Usually this doesn’t even require a skill check. Camp patrols are under orders to immediately respond to attacks or other crises, and that’s what they will do.
Enemies who are currently asleep, on break, or otherwise not ready for a fight are called reserves. All reserves act like guards except in that they will not actively watch for or engage intruders. If they happen to detect intruders, they will sound an alarm and the specific reserve group which detected them may even engage, but the reserves in general will usually need at least one round to prepare to engage even if they’re in the same section as attackers. If asleep, anyone wearing heavy armor won’t have time to don it in the full round the reserve unit takes to prepare itself, so either that unit must spend at least ten rounds armoring themselves or else any heavy armored members of the unit must go into battle unarmored (they can still grab a shield and put on components of their armor that qualify as lighter armor by themselves, for example someone who wears full chain will have enough time to put on their chain shirt and someone who wears full plate will have enough time to strap on their breastplate). Reserves which are on break will be fully armored but will still need a full round to grab all their weapons and form up for battle, however they will be fully armed, armored, and ready to go after just one round. Reserves who are on duty specifically as reserves don’t need any time to get ready for a fight, and instead will immediately begin moving out when they receive orders, however they will still not actively defend the section they’re in like guards would until they receive orders to begin behaving like guards. Any reserve unit that hears the sounds of battle will immediately begin readying themselves for battle and, once ready, will become a guard unit.
Assaulting a War Camp with Allies
Sometimes players will bring units from an allied war camp to help them sack an enemy war camp, and other times an enemy war camp might send an attack to a friendly war camp where the players are staying. Depending on the war camp that’s attacking, usually either one or more lieutenants and all of their troops will empty out of whatever section of the war camp they stay in to attack the other, or else the camp will send some number of their hex patrols, reserves (especially dedicated reserve units, rather than ones that are sleeping or on break), camp patrols, or even spare guard units to help with the attack. Sending hex patrols is a comparatively small favor to sending guard units or camp patrols, and likewise sending weak groups is a comparatively small favor to sending strong ones.
Regardless of exactly what units arrive, when units are fighting one another in sections the PCs aren’t in, you don’t want to roll out individual attacks. Instead, give each unit battle strength equal to double its average CR (round up), and have units pair off and fight for three rounds (about how long most melees last in 5e). At the end of three rounds, they make opposed battle strength checks at each other. The winner loses half its units starting with the lowest CR and working up, and the loser is totally destroyed. For every 2 points by which the winner exceeded the opponent’s battle rating, one unit is saved.
If one side outnumbers the other and multiple units gang up on an enemy unit, the highest CR unit makes the roll, and any units of the same or higher CR as the target enemy add an extra 50% to their side’s total battle rating, any units 1-3 CR lower than the enemy add 25%, any units 4-6 lower add 10%. Units 7 or more CR lower can add a 10% unit only if they pair up with another unit 7 or more CR lower. If reinforcements show up to the melee partway through, they can add their bonus to the battle roll, but they cannot make the roll themselves (so if a CR 3 unit is fighting another CR 3 unit and a CR 4 unit arrives to reinforce them, the CR 4 unit adds a 50% bonus to the CR 3’s +6 roll, but the CR 4 unit cannot make its own +8 roll and take the 50% bonus from the CR 3 unit instead, however after the melee resolves the CR 4 unit can then engage other units on its own).
When counting casualties from the victorious side of the fight, remove creatures starting with the lowest CR amongst all of the victorious units. If the more numerous side loses, the unit who began the melee is totally wiped out, and one creature per every 2 points they lost the roll by is taken from the other units, starting with the lowest CR between them, much like the winning side but in reverse.
All percentages are added as percentage points, so if you have a +4 unit with a 50% bonus and a 25% bonus, that is a 75% bonus or a +3. Any fractions are rounded down. To figure out weird totals like an 85% bonus to a CR 7 unit’s +14 roll, just punch 14 * 1.85 into your phone or laptop calculator and ignore everything after the decimal point (in this case, the result is 25).
All of this is easier in practice than in explanation, but nevertheless it does add some extra bookkeeping keeping track of when melees started, when they resolve, and who is at what CR. Major engagements between war camps should not be typical. Even a very militant campaign in Thar should generally expect to have such a battle only once every three or four sessions, rather than moving straight from one camp battle to another.