OPlayTCG is an unofficial fan-made platform for the One Piece Card Game, bringing card research, deck building, and online play together in one browser-based service. Its structured library covers cards and printings across seven languages, with search filters for details such as color, type, rarity, attribute, archetype, cost, and counter. Users can explore sets, spoilers, card effects, alternate arts, promos, and reprints, while checking current Standard and Extended legality.

The deck builder lets players choose a Leader, assemble a 50-card deck, and receive live validation for colors, copy limits, format, and rotation. Deck lists can also be imported, exported, and saved. For play, OPlayTCG offers a rules-accurate simulator with online 1v1 matchmaking, ranked or casual games, private rooms, recorded replays, and a per-player clock. Players can also join or organize tournaments featuring Swiss and single-elimination brackets. A guided tutorial introduces newcomers to the game and simulator, and users can explore the library without an account. OPlayTCG is not affiliated with or endorsed by Bandai.