Players can app up to two characters per round. (Note that players can have a maximum of three characters in-game.) Information about appable characters can be found here.
The City has a cast cap of 10 characters per standalone canon and 15 characters per large franchise (e.g. MCU, DCEU, Star Wars, etc). Please visit the taken page to see which casts are at or nearing their cap.
For all relevant game resources, visit the game navigation. Please post any game-related questions you may have to the FAQ. The mod team will not be responding to questions in this plurk.