Can I build a deck together with friends on TCGSwap?

Yes. Every deck on TCGSwap has a Collaboration Space. You can invite up to 5 friends; they can suggest card changes, discuss ideas, and playtest proposals. You review and apply suggestions before anything changes in your deck.

How does deck collaboration work?

It works like a pull request for your deck. Collaborators open the deck editor, make their proposed changes, and submit a suggestion with a note. You get notified, open the comparison view to see exactly what they changed, and choose to apply all, cherry-pick individual cards, or decline. Nothing changes in your deck until you approve it.

Can collaborators chat and discuss the deck?

Yes. The Collaboration Space has a shared group discussion thread for the whole deck, plus a per-suggestion Q&A thread for each proposal. You can @mention teammates and link specific cards inline.

Is collaborative deck building free?

Yes, collaboration is free for all TCGSwap users during beta. You can invite up to 5 collaborators per deck.

Does TCGSwap work for MTG, Pokémon, Yu-Gi-Oh and One Piece collaboration?

Yes. The Collaboration Space supports all four games — Magic: The Gathering, Pokémon TCG, Yu-Gi-Oh and One Piece. Format validation and card prices are included for each game.

Underground Sea · Summer Magic / Edgar 290/306

Underground Sea (Summer Magic / Edgar 290/306), Rare, Land — Island Swamp. Market price €280.00, unchanged this week. Illustrated by Rob Alexander. Prices are estimates from TCGPlayer and Cardmarket, not guaranteed values.

Weekly price history

Week	Market price
2026-W31	€280.00
2026-W32	€280.00
2026-W33	€280.00
2026-W34	€280.00
2026-W35	€280.00
2026-W36	€280.00
2026-W37	€280.00
2026-W38	€280.00
2026-W39	€280.00

Questions

How much is Underground Sea 290/306 worth?

Underground Sea from Summer Magic / Edgar (290/306) has a market estimate of €280.00, unchanged this week. Prices are estimates from TCGPlayer and Cardmarket.

Is Underground Sea 290/306 rare?

It is a Rare from Summer Magic / Edgar, a 306-card set.

Browse more Magic: The Gathering cards · All Summer Magic / Edgar cards · Build a deck · Track your collection