Oracle

Enchantment 

At the beginning of your upkeep, exile the top card of your library.
During your turn, if an opponent lost life this turn, you may play lands and cast spells from among cards exiled with Theater of Horrors.
3R: Theater of Horrors deals 1 damage to target opponent or planeswalker.

Tournooi-info

Legal in: Vintage, Legacy, Modern, Commander

Officiele rulings

2019-01-25 - wotc
Damage dealt to a player causes that player to lose that much life.

2019-01-25 - wotc
Theater of Horrors doesn't change when you can play the exiled cards during your turn. For example, if you exile a sorcery card, you can cast it only during your main phase when the stack is empty. If you exile a land card, you can play it only during your main phase and only if you have an available land play remaining.

2019-01-25 - wotc
Casting an exiled card causes it to leave exile. You can't cast it multiple times.

2019-01-25 - wotc
In a multiplayer game, if an opponent loses life during your turn and then leaves the game, you can play cards exiled with Theater of Horrors.

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