Editing Stars Without Number: Back in Black (section)

=== Swarms ===
*Swarms are a mechanical way to represent fights with very large groups of enemies.
*A swarm's Strength is equal to the number of creatures in the swarm.
*A swarm's HP is equal to the average HP of a member of the swarm.
*A swarm's other stats, such as AC, Movement Rate, saving Throws, et cetera, remain the same.
**An attack that deals less damage than the swarm's HP has no effect
**An attack that deals damage equal to or greater than the swarm's HP reduces its strength by 1.  Some weapons listed below can reduce strength by more than one per attack.  For each multiple of the swarm's HP, Strength is reduced by one, up to the limit of that weapon.
**Bursts of automatic fire can reduce strength by up to 3.
**Area effect weapons deal double damage and do not have an upper limit on the amount of Strength they can remove, so long as in the referee's judgment the area could include that many creatures.  Reductions to damage from a successful save (The Swarm only makes a single save) or from having a low AC (as in the case of grenades) is applied before doubling.
**Suppressive fire weapons deal double damage instead of half damage, and have no limit on how much they can reduce enemy Strength.  If the swarm is under hard cover, they can make a save as normal.
**PCs with combat/primitive or combat/unarmed, who are using those skills, may make a number of melee or unarmed attacks equal to their skill rating +1 if the swarm is in melee with them, and they are using that type of attack.
**A group of enemies must have Strength at least double the number of PCs to be considered a swarm.  They only make one attack per PC (Ranged or melee, as appropriate.)  However, for every full multiple of the PCs number their strength is (double, triple, quadruple...) the swarm's attacks gain +1 to hit and damage.
**A swarm with Strength equal to at least four times the number of PCs may deal 1d4 damage (with no bonus) to PCs who are in powered armor or the equivalent, even if their weapons would normally not be able to affect an opponent in that type of armor.  This still requires a successful to-hit roll.