You can only normal summon once per turn,when you normal summon put a monster in either face up atk or def. You can also set only on monster per turn, but setting is like normal summon so you can only pick one of these.Setting is putting face down monsters,once face up you can not put face down again.Flip effects only work when it's face down and gets flipped face up.
Atk and Def are important atk monsters can atk def can't. Each player has something called life points you lose when you lose all your life points.Each player starts ou with 8000 life points.When you atk some monster,(when they are both in atk,) with lower atk,(pretend a monster with 1200 atk atks a monster with 800, the monster with 800 atk takes the distance of damage which is 400 in this occation.)When your monster atks someone with higher atk you take damage and your monster gets sent to the graveyard.When their atk is the same neither one dies and neither player takes damage.When your monster atks a def monster with lower def destroy it no one takes damage. When your monsters atk is weaker you take damage. If they are the the same both monsters survive and no one takes damage.
Effects do what it tell you to do.
Spell and traps can only be activated if they're face down in the spell or trap zone.
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