RWBY Combat Ready Expansion Lil' Miss Sub-Boss Expansion Pack includes 18 new Sub-Boss cards and 1 new objective card to add this new enemy to battle in your RWBY: Combat Ready Core Game. *Requires a copy of the RWBY: Combat Ready Core Game to play. RWBY: Combat Ready is a cooperative board game where 2-5 players join forces to take on fierce RWBY villains and slay monstrous Grimm! Players play as one of the four main heroines in the series: Ruby, Weiss, Blake, or Yang along with Penny. Each player has their own separate deck of cards representing their attacks, actions, and moves. Each character plays a little differently, using their own unique tactics and strategies.