Flip monsters (Japanese: リバースモンスター Ribāsumonsutā "Reverse Monster"), formerly Flip Effect Monsters (リバース
Previously, Flip Effects (as they were capitalized at the time) were a type of card effect like Trigger and Ignition Effects, with Flip Effects being able to be identified by the text "FLIP:" at the start of the effect; Flip Effect Monsters were simply monsters that had a Flip Effect. Starting in Starter Deck 2014 (in the OCG) and Super Starter: Space-Time Showdown (in the TCG), Flip is treated as an ability and the word "Flip" is written on the cards' Type/Ability line.
A Flip effect is a type of Trigger Effect that is preceded by "FLIP:". This kind of effect meets its activation timing when the Flip monster on the field is flipped from face-down to a face-up (even during the Damage Step).
Flip effects are exclusive to Flip monsters. While there are other monsters that have effects that activate when they are flipped face-up, these are not Flip effects.
- There are currently no Cyberse, Dinosaur, Fish, or Wyrm-Type Flip monsters.
- Flip monsters are rarely used in the anime; in the anime, prior to Yu-Gi-Oh! ZEXAL, it was legal to Normal Summon a monster in face-up Defense Position, and monsters were rarely Set.
- "Performapal Momoncarpet" is the only Pendulum Flip monster.
- The only characters to have a Deck based on Flip monsters are (the appropriately-named) Flip Turner from Yu-Gi-Oh! ZEXAL, Aura Sentia from Yu-Gi-Oh! ARC-V and Akira Zaizen from Yu-Gi-Oh! VRAINS.
- "Subterror Behemoth Ultramafus" has the highest Level and original ATK of all Flip monsters, being Level 12 with 3000 ATK.
- "Pot of The Forbidden" has the highest DEF of all Flip monsters, with 3000 DEF.
- "Aroma Jar" is the first Flip monster to not have a Flip effect.
- The illegal card "Masahiro the Dark Clown" is the only Flip monster to have flavor text.