Only the first main phase each turn is considered a precombat main phase, even if other combat phases are created (with Relentless Assault, for example).
04-10-2004
wotc
It will not trigger a second time in a turn, even if you cast a spell that gives you a third main phase.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.