REDU format ruling
Reverse Trap
Nearest-era rulings (Tengu, Sept 2011) — no REDU-specific archive exists.
Card effect (current official text)Until the End Phase, all effects that add or subtract ATK or DEF are reversed. (Additions now subtract, and subtractions now add, instead. Multiplications and divisions, including halving/doubling, are not affected.)
Rulings
- If a card gives a monster +100 ATK, and Reverse Trap is activated, that monster now has -100 ATK instead. This card only affects increases and decreases of a defined value, such as +200 (which becomes -200) or -500 (which becomes +500). It does not change cards which double, half, or reduce to 0 the ATK or DEF of a monster.
- You cannot activate this card during the Damage Step. This card affects monsters, Spell Cards, and Trap Cards controlled by both players.
- Additional Reverse Traps activated in the same turn will have no effect. So Reverse Trap will change Axe of Despair’s effect of adding 1000 ATK to subtracting 1000 ATK. If a second Reverse Trap is activated, the equipped monster still has -1000 ATK.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the REDU forum — sourced change requests get reviewed.