Book of Moon

Well i was dueling against Buntaga21 and i booked EH Gaia, in the same turn before end his turn he flipped gaia face up, he said he read that he could do that in some place, can somebody explain to him how this work? i think i didnt explained well to him

thanks

Wrong thread, moved to Card Questions.
About your question, when a monster is flipped face-down in the same turn it's summoned, it can be flipped face-up.

Just to make it clear, I summoned Gaia the turn before and since I haven't changed his battle position manually, during this turn, I was able to flip him face-up, right? Since you wrote for the turn he was summoned.

If Gaia wasn't summoned in that turn, had declared an attack that turn or buntaga had manually changed his battle position that turn, then he could flip summon it in the same turn it was Book'ed.

A monster cannot change it position manually on the turn it was summoned or after declaring an attack.

If you use Book of Moon on a monster that has not met either of those 2 conditions, then the monster can be flip summoned on the same turn.

Ok, now that sets a new question for me...When you activate Book of Moon during a monsters attack and it flips that monster, does it count that the monster attacked??