There are three known Gain abilities:
- Infantry Gain Health - Exclusive to Shoulder to Shoulder, all friendly infantry in play gain Health Plus X for X equal to number of infantry in play minus 1. 3 infantry cards in play means Health Plus 2. The effect lasts until the unit is killed or unsummoned.
- Artifacts Gain Pay Life 2 - Exclusive to Power Drain, all enemy artifacts in play (excluding reserve) gain Pay Life 2, that means it can eventually kill the unit equipping the artifact. It is unknown if immune can block the spell effect.