Transaction Rollback Copying a Cost-Bundled Trap (Eradicator Epidemic Virus) — Confirm With a Head Judge

Transaction Rollback is one of the cards experienced players say to "just ask the Head Judge" about. It copies another Normal Trap's effect without paying that trap's cost (the general mechanic lives in Effect-Copying Cards), and that cost/effect split gets genuinely hard when the copied trap bundles a declaration or a value into its cost. The marquee case — copying Eradicator Epidemic Virus — was ruled inconsistently for a long time and only stabilized at recent TCG events; treat it as low confidence. For the general class of genuinely-unsettled rulings, see When to Ask a Head Judge.

Relevant card text

Transaction Rollback — "Pay half your LP, then target 1 Normal Trap in your opponent's GY, except 'Transaction Rollback'; this effect becomes that card's activation effect. You can banish this card from your GY and pay half your LP, then target 1 Normal Trap in your GY, except 'Transaction Rollback'; this effect becomes that card's activation effect. ..."

Eradicator Epidemic Virus — "Tribute 1 DARK monster with 2500 or more ATK, and declare 1 type of card (Spell or Trap); look at your opponent's hand, all Spells/Traps they control, and all cards they draw until the end of their 3rd turn after this card's activation, and destroy all cards of that declared type."

In Eradicator Epidemic Virus the semicolon is the divider: "Tribute 1 DARK monster with 2500+ ATK, and declare 1 type" is the cost; "look at your opponent's hand … and destroy all cards of that declared type" is the effect.

The verdict, and why it needs a Head Judge

Current TCG ruling (recent Tier-3 Head-Judge consensus; Dueling Book adopted it 8 Dec 2024): yes, Transaction Rollback can copy Eradicator Epidemic Virus and the copied effect applies fully. You re-declare Spell or Trap when you activate Transaction Rollback (a declaration is part of the activation procedure, so it carries into the copy), you do not pay Eradicator Epidemic Virus's Tribute (a copier never pays the copied card's cost), and the continuous "look at hand / destroy the declared type through their 3rd turn" effect then resolves.

But this is low confidence — confirm with your Head Judge before relying on it. This interaction was ruled differently at different times and places: an earlier/strict reading held that, because the Tribute-and-declare is a cost Transaction Rollback does not copy, the copy had nothing to act on and "you can't just copy Eradicator Epidemic Virus to nuke all Spells/Traps" — the same logic that makes Burst Breath an illegal target (see below). It took explicit Head-Judge clarification and event-level consensus to settle on "it works," and OCG handling and older TCG handling have not always matched. Because the cost line bundles a declaration the effect depends on, this is exactly the kind of card whose unusual targets you should clear with the Head Judge at an event.

The general principle — declaration/choice vs. cost-produced value

This is the line that separates Eradicator Epidemic Virus (copyable) from Burst Breath (not):

• A declaration or choice the effect later references (declare a type, choose an option) is part of the activation procedure. It carries into the copy — you simply make the declaration/choice again when you activate Transaction Rollback. The effect has what it needs.
• A value produced by the cost itself does not carry, because the copier skips the cost. Burst Breath Tributes a Dragon as a cost and then destroys monsters with ATK ≤ that Tributed Dragon's ATK; with no Tribute there is no Dragon and no ATK value, so the effect has nothing to key off and Burst Breath is not a legal target. See the Burst Breath bullet in Effect-Copying Cards.
• Eradicator Epidemic Virus only needs the declared type (which carries) and does not need the Tributed monster for its destruction to function — that is the mechanical reason the copy can work even though the Tribute is skipped.

Judge calls to watch for

• Treat Transaction Rollback copying a cost-heavy or cost-bundled trap as a low-confidence, ask-the-Head-Judge question, not a clean yes/no. Surface that explicitly.
• For Eradicator Epidemic Virus specifically: the current TCG consensus is that it works (re-declare the type, skip the Tribute, apply fully), but state that it was contested and tell the player to confirm with their Head Judge.
• Keep the distinction sharp: a declaration/choice carries into the copy; a cost-produced value does not. Do not generalize "EEV works" into "any cost-dependent trap works" — Burst Breath-style traps remain illegal targets.
• Do not silently present one era's or one region's stance as settled TCG fact when the ruling history is split.

Sources

• Card text via YGOPRODeck API: Transaction Rollback, Eradicator Epidemic Virus.
• Dueling Book Head-Judge Q&A, "Transaction Rollback vs. Eradicator Epidemic Virus" (update 8 Dec 2024 — copy applies fully, adopted to match recent TCG Tier-3 Head-Judge rulings): https://forum.duelingbook.com/viewtopic.php?t=31140
• "Ruling Problems of Transaction Rollback (HJ clarification required)" — https://www.youtube.com/watch?v=ZjQWbIuAn7I
• Transaction Rollback copies the effect, not the cost; activation conditions still required; re-declare a declared type; cost-dependent traps such as Burst Breath are illegal targets: Yugipedia "Card Rulings:Transaction Rollback"; Pojo "Transaction Rollback" Card of the Day.