ChoomBattler is an unofficial, fan-made online simulator for the Cyberpunk Trading Card Game. It lets players build decks and play for free in a web browser on desktop or phone, with no download or account required. The simulator automates every card in the available pool, including timed abilities, reaction windows, and delayed effects, so game rules are handled during play.

Players can practise offline against one of three bot difficulties, share a screen for a local game, invite a friend to play online, or compete against other players on the ranked ladder. Online matches support the Core or Demo card pool and best-of-one or best-of-three formats; ranked play includes Elo ratings, six rank tiers, and a leaderboard. ChoomBattler also offers a deck builder with live legality checks, text-based deck import and export, and poster-image exports. New players can learn through a guided tutorial and concise guides to gameplay, keywords, and deck building.