by Alex319
"Legendary" = only one can be on the battlefield at any time. So if you play one, that stops your opponent from playing one."Epic" = Only one can be in each player's spellbook.
"Unique" = Each player can have only one on the battlefield at any one time. So you can have two in your spellbook to replace it if it gets destroyed, but you can't put both out at the same time.