The substitution pack adds a whole new dimension to Rugby: The Game. RTG plays great as the base game, but adding subs creates an exciting new dynamic to really get the adrenaline pumping.
Firstly we have the Star players. Two full teams of them! These guys are on another level, with better stats and a few player-specific abilities that give them the edge. The overall gameplay is still pretty balanced, but played right, you know when these guys are on the field!
The players can only come on when you use one of your substitution cards (generally 5 in a game). These cards have rules which dictate when they can be used, and are determined by points-difference, total points scored, game stage (such as "play at half time"), and such. Also, the player is randomly selected (with the subs card dictating "Forward" or "Back" deck only), so you don't know who you will get. Oh, the anticipation is already killing me!
-description from publisher