After the Battle Phase, the Turn Player enters Main Phase 2 (メインフェイズ２, Meinfeizu Ni). In this Phase, any action that could normally be performed in Main Phase 1 can occur, as long as the requirements are met (i.e. no more than 1 Normal Summon or Set).
In Main Phase 2, the Turn Player may:
- Normal Summon, Tribute Summon, or Set a monster if you have not already done so in Main Phase 1.
- Special Summon a monster(s).
- Manually change the Battle Position of a monster, provided that monster did not declare an attack during the Battle Phase, and provided that it was not Set, Normal Summoned, Flip Summoned, or Special Summoned this turn.
- Perform a Flip Summon on a Monster Card, provided it was not Set or Summoned in Main Phase 1.
- Activate effects, such as those of "Barrel Dragon" or "Blowback Dragon" if they have not been activated in Main Phase 1.
- Activate effects like "Cannon Soldier's" effect that can only be activated during the Main Phase, but can be used more than once per turn.
- Activate or Set Spell and/or Trap Cards of any speed. Quick-Play Spell Cards and Trap Cards cannot be activated in the turn they are Set.
If a particular monster wasn't Summoned this turn, the Turn Player can flip it face-down using its effect (such as with "Guardian Sphinx" or "Swarm of Scarabs"), and then perform a manual Flip Summon on it, since the rules state that one manual Battle Position change may be performed per turn.