Historical Rules · 1 November 2013
Rule 207.2c
Official source text from the 1 November 2013 Rules release
An ability word appears in italics at the beginning of some abilities. Ability words are similar to keywords in that they tie together cards that have similar functionality, but they have no special rules meaning and no individual entries in the Comprehensive Rules. The ability words are battalion, bloodrush, channel, chroma, domain, fateful hour, grandeur, hellbent, heroic, imprint, join forces, kinship, landfall, metalcraft, morbid, radiance, sweep, tempting offer, and threshold.