Rust
Instant
Counter target activated ability from an artifact source. (Mana abilities can't be targeted.)
Legalities
- brawl: banned
- commander: legal
- legacy: legal
- modern: legal
- pauper: legal
- pioneer: banned
- standard: banned
- vintage: legal
Rulings
- 2004-10-04:
Can’t be used on mana abilities because they don’t use the stack. They’ve already resolved by the time you get priority.
- 2016-06-08:
Activated abilities contain a colon. They’re generally written “[Cost]: [Effect].” Some keywords are activated abilities and will have colons in their reminder text.