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.

War Rock Mammud · Lightning Overdrive Premiere! promotional card 84903021/1

War Rock Mammud (Lightning Overdrive Premiere! promotional card 84903021/1), Common. Market price $0.16, unchanged this week. Prices are estimates from TCGPlayer and Cardmarket, not guaranteed values.

If you control no monsters, or all monsters you control are Warrior monsters, you can Normal Summon this card without Tributing. If your EARTH Warrior monster battles, after damage calculation: You can target 1 Spell/Trap your opponent controls; destroy it, then all "War Rock" monsters you currently control gain 200 ATK until the end of your opponent's turn. You can only use this effect of "War Rock Mammud" once per turn.

Weekly price history

Week	Market price
2026-W31	$0.13
2026-W32	$0.14
2026-W33	$0.14
2026-W34	$0.14
2026-W35	$0.14
2026-W36	$0.15
2026-W37	$0.15
2026-W38	$0.16
2026-W39	$0.16

Questions

How much is War Rock Mammud 84903021/1 worth?

War Rock Mammud from Lightning Overdrive Premiere! promotional card (84903021/1) has a market estimate of $0.16, unchanged this week. Prices are estimates from TCGPlayer and Cardmarket.

Is War Rock Mammud 84903021/1 rare?

It is a Common from Lightning Overdrive Premiere! promotional card, a 1-card set.

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