Arcane Laboratory
Enchantment
Each player can't cast more than one spell each turn.
It soon became obvious that some experiments were best overseen by fireproof teachers.
Stephen Daniele
Urza's Saga (USG)
• #60Rulings
When it leaves the battlefield, the effect ends and all players are able to cast spells unrestricted again.
(wotc • 2004-10-04)
When Arcane Laboratory enters, it will look back over the turn to see if any spell was cast before it entered the battlefield. It will notice itself being cast.
(wotc • 2004-10-04)
If a spell is countered, it still counts as the one spell cast.
(wotc • 2004-10-04)
Rulings
When it leaves the battlefield, the effect ends and all players are able to cast spells unrestricted again.
(wotc • 2004-10-04)
When Arcane Laboratory enters, it will look back over the turn to see if any spell was cast before it entered the battlefield. It will notice itself being cast.
(wotc • 2004-10-04)
If a spell is countered, it still counts as the one spell cast.
(wotc • 2004-10-04)