Kill them all!
Henzell says...
  1. In 0.8 and earlier, "senselessly" repeating an action when your XP pool has XP in it, in order to spend XP on the skill associated with that action.
  2. For example, casting magic dart at the wall, evoking blink off an artifact, hitting a plant (up to skill level 1), dodging shadow dragon breath with rN+++, letting a mimic hit you, or invoking god abilities. Use 0 to repeat an action.
  3. <mikee_> i died with tornado once because i held down . while letting a hobgoblin hit me <mikee_> to train shields

Information based on master branch and the great LearnDB.
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