Gemini monsters (Japanese: デュアルモンスター Dyuarumonsutā "Dual Monster") are Effect Monsters with the ability "Gemini". They have effects, but these effects must be "unlocked" by performing an additional Normal Summon on them while they are face-up on the field; until then, they are treated as Normal Monsters on the field and in the Graveyard (everywhere else they are treated as Effect Monsters). The "Chemicritter" archetype is heavily focused on, and almost completely composed of, Gemini monsters. Many of the "Red-Eyes" monsters introduced in Series 9 are Gemini monsters.