Main Phase 1

Main Phase 1 occurs after the Standby Phase.

In Main Phase 1 you may:


 * Normal Summon, Tribute Summon, or Set 1 monster.
 * Special Summon 1 or more monsters.
 * Manually Change the Battle Position, or perform a Flip Summon on, a [Monster Card, providing it was not Set or Normal/Tribute Summoned this turn
 * Activate effects, such as those of Barrel Dragon or Blowback Dragon
 * Activate or Set Spell and/or Trap Cards. Quick-Play Spell Cards or Trap Card cannot be activated in the turn they are Set.

You can flip a Monster Card face-down, as per it's effect (Such as with Guardian Sphinx or Swarm of Scarabs), and then perform a Manual Flip Summon, since the rule only states one Manual Battle Position change per turn.

At the conclusion of Main Phase 1, you may then choose to enter the Battle Phase. If you choose not to, you automatically proceed to the End Phase.