How this site works
What this site does
UnionArena TCG is a community-built database and resource hub for Bandai's Union Arena trading card game. It indexes every card across all titles and sets, collects tournament decklists, and tracks daily TCGplayer market prices.
Everything is free. No accounts, no paywalls. Card pages link to TCGplayer with affiliate tagging, which is how the site covers hosting costs.
Data pipeline
Card data refreshes daily from TCGCSV, which mirrors TCGplayer's full Union Arena catalog, so new cards appear as soon as TCGplayer lists them. Tournament results are collected daily from English-language events: store tournaments, online weeklies and Regional top cuts.
- 84 sets: boosters, extra boosters, starter decks and promo groups
- Top-8 decklists from English tournaments with at least 8 players
- Daily TCGplayer market prices on every card
Tools
- Card database
- Every Union Arena card, searchable by name, title or effect text and filterable by color, type, energy and keyword. Each card has a detail page with alternate printings and TCGplayer prices.
- Deck builder
- 50-card deck builder that enforces the single-title rule, the 4-copy limit and the Special, Color and Final trigger caps. Decks are shareable by URL.
- Tournament decklists
- Top-cut decks from Union Arena events with the full card list, a one-click export and a TCGplayer buy link.
- How to play
- Deck-building rules, card anatomy and trigger types, with a link to Bandai's official rules.
Technical details
The site is built with Astro (fully static, no server runtime) and hosted on Cloudflare Pages. Every page is pre-rendered at build time and served from Cloudflare's edge network.
Disclaimer
UNION ARENA and all related names are trademarks of Bandai Co., Ltd. Card names and artwork belong to their respective rights holders. This site is unofficial and not affiliated with or endorsed by Bandai. Card images and game text are used for informational purposes.