Microworld has modular rules that you combine to create several different scenarios. This promo supplies two new additional rule tiles that you can add to the base game to increase the variability of the game even more. The first additional rule (C1) applies during the setup. Players will have a common special ability during the game. Moreover, you will find a bonus Mutation Tile in the promo. The second additional rule (H1) applies at the end of the game. If players are able to control a tissue alone, they will score two more points.