Reinforcement cards +_ are cards that can boost one side of the encounter. They can be played after encounter cards are revealed in the Reveal phase, by either main player or by any ally, to increase either side's total (the player's side or the opponent's side) by the value of the reinforcement, and are discarded after use. Reinforcements in the cosmic deck have values from +2 to +5 (or up to +8 with the Cosmic Alliance large group deck).

There is no rule against playing reinforcement cards on  N s, but doing so has no effect.

Cosmic Card (FFG) Cards Cosmic Card (FFG)
ARTEncounter card (23 N  M  R ) • FLA29×2+5 3