Mass Combat in the 41st Millenium
A fan-made supplement by Leo E Gunnemarsson
What follows is an attempt at mass-combat rules for the 40k roleplaying games since I’m
not satisfied with the current ones.
Base Rules
As a base this mass-combat system utilizes the rules for extended tests. However rather
than having one skill or characteristic tested against it is up to the players to come up
with ways to help the war-effort and roll for them. Occasionally this will be broken up
with Flashpoints.
Step One: Deciding Difficulty
Two things are needed to make this, the first is to decide a quality of the enemy, this is
done simply by choosing a value between 30 (Conscripts) and 100 (Titan Legion). This
will be the value rolled against by the enemy. Should the GM wish it is good to have
some characters supporting the enemy as well and allow them to take some of the rolls
as per the same rules as the players.
Below is a list of strengths and what they can represent:
Strength Represents
30 Conscripts, Unsupported Feral Worlders
40 PDF force, Planetary Warbands
50 Fully supported Astra Militarum Army,
Orc Warband, Kroot Kindred, Tyranid
Invasion
60 Dark Eldar Raiders, Exodite Force, Tau
army, Craftworld Army
70 Daemon Incursion
80 Adeptus Astartes Company, Knight House,
Necron Dynasty
90 Astartes First Company
100 Titan Legion
After choosing the enemy strength it is time to decide how many successes each force
needs to achieve victory. This depends on the kind of conflict it is but is later modified
for each side, the below may be modified at the GMs discretion to fit his battle. For
Sieges the lower value is for the defender while the higher is for the attacker.
Conflict Size Successes needed
Skirmish 12
Battle 24
Siege 24/30
Large Battle 36
Long Siege 36/40
The successes needed will then be modified for quantity of troops, these modifiers will
be added to one side only, when calculating this count a vehicle as ten troops (may be
modified by the GM if needs be) not counting crew:
Number of Troops Modifier to outnumbered
Roughly Equal 0
Outnumbered by 10% +1
Outnumbered by 25% +3
Outnumbered by 33% +4
Outnumbered by 50% +5
Outnumbered by 66% +7
Outnumbered by 75% +9
Outnumbered 2 to 1 +10
Outnumbered 3 to 1 +20
Outnumbered 4 to 1 +30
Each further increase in outnumber ratio: +10
(ie 4 to 1 increased to 5 to 1)
Step Two: Take the tests
The two sides then take turns taking the tests for the conflict starting with the attacker.
Note that each test must be described as helping the war effort in a way. These shouldn’t
merely be the players rolling dice however, it should be them making strategies and
actions before reacting at their opponent doing the same. Often the group should be able
to discuss their actions together and choose strategies accordingly.
Flashpoints
Flashpoints are moments during the battle where the players more directly affect the
battle. These are created by the actions and tests of both sides and can be created in
different ways. The GM normally decides that they should turn up as result of an action
(perhaps the players decide they themselves should make a commando-raid against a
strategic target or perhaps one of the players thinks his equipment is ideal to help
handle a new situation) then the GM can just create a small encounter around that. The
players can also request a flashpoint should they wish in which case the GM either says
no or creates one. A successful or failed flashpoint will then count as a number of
successes (for the players or the enemy) decided by the GM. It may be a good idea to
have a few backup characters for flashpoints so that less active players can participate
with borrowed NPCs on their side.
Step Three: Declare Victory and Play Out Defeat
As one side reaches their needed number of successes they win. The GM should then
consider by how much they win and what this should mean. A defeat need not be a
whole enemy force slaughtered, most of the time it is one side forced to retreat and
relinquish control of a place, this should be decided by the GM however. One side can
also take actions when close to the end to mitigate the cost of a loss (such as ordering an
organized retreat), such actions never contribute their degrees of success to who wins
but if successful will make a defeat less costly.
