Gemini

Could somewone teach me about thoose cards?

Gemini Monsters (known as Dual Monsters in the OCG) are a type of Effect Monster. 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 (known in the OCG as a Second Summon). Until then, they are treated as Normal Monsters on the field and in the graveyard. You can not special summon Gemini's from the hand or the deck by abilities that supports normal monsters, like Ancient Rules.

All Gemini Monsters to date are treated as Normal Monsters while they are face-up on the field before being Gemini Summoned, or while they are in the Graveyard. If they exist anywhere else, they are treated as Effect Monsters.

The process of Gemini Summoning a Gemini Monster (that is being treated as a Normal Monster by its effect) is just the same as performing any other Normal Summon, except that the monster is already on the field and you don't have to Tribute monsters for Gemini Monsters of Level 5 or above. You cannot Gemini Summon a Gemini Monster that has already been Gemini Summoned (and is still considered to have been Gemini Summoned).

Once a Gemini Monster has been Gemini Summoned, it is then treated as an Effect Monster and it gains the effect(s) written on it.

While this entire process seems very troublesome to go through for just one monster, note that Gemini monsters usually have extremely powerful effects, often without a drawback.



I copied this from wikia, because i was too lazy to explain, anyway this should explain all