There are only two Main Phases to enter.
After the Standby Phase, the Turn Player automatically enters Main Phase 1. In Main Phase 1, the Turn Player may:
- Normal Summon, Tribute Summon, or Set a monster.
- Special Summon a monster(s).
- Manually change the battle position or perform a Flip Summon on a Monster Card, provided it was not Set or Summoned this turn.
- Activate effects, such as those of "Barrel Dragon" or "Blowback Dragon".
- 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 only one manual Battle Position change may be performed per turn; Battle Position changes by effects do not count towards this.
At the end of the Battle Phase, the Turn Player can enter Main Phase 2 instead of the End Phase. In Main Phase 2, the Turn Player may do the same things done in Main Phase 1 if have not been perform to do so. If the Turn Player has Normal Summoned or Set during the Main Phase 1, you cannot Normal Summon or Set as these actions can only be done once per turn. If the Turn Player have not manually change the battle position of a monster that has not been Summoned this turn, the Turn Player can perform this action.