What it does
There's no standard MTG keyword called "Thunder." It's not an evergreen or named keyword ability in the rules, so if you saw it on a card, it's almost certainly part of a card's name (like Thunderkin Awakener, Thundermaw Hellkite, or Thunderbreak Regent) or flavor text rather than a mechanic you need to learn.
The common mix-up: players sometimes confuse it with actual keywords like "Trample" or with the "Thunder" in card names that have nothing to do with one another rules-wise. Each of those cards just does whatever its individual text says—there's no shared "Thunder" rule linking them.
In Commander, just read the specific card's abilities. If you encountered "Thunder" somewhere specific, double-check whether it's a token name, a creature type reference, or part of a longer keyword you misread.
Iconic cards with Thunder
See all 1 →