What is flipped about?

Flipped is a term used when a monster is switched from Face down defense Position, to face up attack position. It is also referred to when a face down defense position monster is switched to face up defense in battle.

Some monsters, known as "Flip effect monsters" have special abilities that only activate when they are flipped. For example, Man-Eater bug is completely harlmess when it's summoned in attack mode. However, if someone were to set it (Summon it in face down defense mode) first, and then flip it on the next turn, it's ability activates. Man-eater bug's effect also activates when it is flipped in battle.