Rooms are private lobbies for playing a series of games with people you invite. Create one, share the room code or invite link, and everyone who joins can play multiple matches in a row without requeueing. Rooms hold between two and eight players and need a linked account, since a room has to persist while people join.
Every room gets a short code and a shareable link. The link carries a rich preview with the room code in it, so pasting it into a chat shows what it is rather than a bare URL. Anyone with either the code or the link can join — there is no friend request step and no approval queue.
A room holds up to eight players even though Infinite Tic-Tac-Toe is a two-player game. The extras are not idle: players who are not in the current match can watch it live, and you can rotate who plays between games. That makes a room work for a small group taking turns rather than only a single pair.
Use a direct challenge from your friends list when you want one game against one specific person. Use a room when you want a session — several games, a group, or people joining partway through. Room matches are unrated, so a long session with friends will not move your ranked rating.