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.

Hallohallo · Circuit Break Special Edition 77994337/4

Hallohallo (Circuit Break Special Edition 77994337/4), Rare. Market price $0.18, unchanged this week. Prices are estimates from TCGPlayer and Cardmarket, not guaranteed values.

[ Pendulum Effect ] Once per turn: You can target 1 face-up monster on the field; roll a six-sided die and that monster's Level becomes the same as the result until the end of this turn. [ Monster Effect ] ''Hallo Hallo, brain of tallow, Guts are gone, noggin's hollow. Seeking sweets and marshing mallows, Watch your back, and your candy sack.''

Weekly price history

Week	Market price
2026-W31	$0.16
2026-W32	$0.16
2026-W33	$0.16
2026-W34	$0.16
2026-W35	$0.16
2026-W36	$0.16
2026-W37	$0.16
2026-W38	$0.18
2026-W39	$0.18

Questions

How much is Hallohallo 77994337/4 worth?

Hallohallo from Circuit Break Special Edition (77994337/4) has a market estimate of $0.18, unchanged this week. Prices are estimates from TCGPlayer and Cardmarket.

Is Hallohallo 77994337/4 rare?

It is a Rare from Circuit Break Special Edition, a 4-card set.

Browse more Yu-Gi-Oh cards · All Circuit Break Special Edition cards · Build a deck · Track your collection