If the target land is an illegal target by the time Molten Rain tries to resolve, the spell doesn't resolve. No player is dealt 2 damage. If the target is legal but not destroyed (most likely because it has indestructible), its controller is dealt 2 damage.
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.
