Fun fact: when and if have two completely different meanings in Yu-Gi-Oh. "When" means that an effect has to happen precisely after the trigger (so if some other mandatory effect happens in between, the "when" effect doesn't happen). "If" is much more flexible and just has to be on the same stack as the triggering effect.
Do other tabletop games use different definitions? I ask because I've always assumed this to be the operative distinction when reading rule books, but, come to think of it, I can't necessarily defend that assumption.
