Cloud Key
Every rules interaction we've explained for Cloud Key, alongside Wizards of the Coast's official rulings. Pick a combo below, or check it against a card we haven't covered yet.
3
Interactions
1
Official ruling
Oracle text
As this artifact enters, choose artifact, creature, enchantment, instant, or sorcery.
Spells you cast of the chosen type cost 
less to cast.
Explained interactions
Official rulings
2021-03-19- Wizards of the Coast · 2021-03-19
The cost reduction applies only to generic mana in the cost of spells of the chosen type you cast.
Official rulings, quoted verbatim via Scryfall. Not AI-generated.
Check Cloud Key with another card
Cloud Key's already in the stack. Add the card you're wondering about.