Enlarge adds 1 Burst to your single-target spells, meaning it registers the attack on every adjacent square to your target. I have an Arcane Skill which gives me 3 in my wizard's deck. Awesome! Let's try it out! First Oops: You don't choose when to play it. It's an orange card that automatically triggers the next time you play a single-target attack spell. Darn. Okay, got it. I remembered that next time and got off several good area range attacks with it. Second Oops: It attacks every square, ally or friend. Hmmm, guess I shouldn't have zapped the bad guy in melee range... I just hit myself and an ally. That wasn't obvious, but it was obvious, shoulda seen that coming. Okay, I got it. I remembered that next time and ran away from bad guys who closed to melee when I had an Enlarge in my hand. Third Oops: Two or more Enlarges in your hand will all trigger on the same spell. They don't override each other, they add +1 burst. Meaning that even after maneuvering away from the bad guy I was about to Arcane Zap, I managed to make it a 2 burst spell, hitting the bad guy and all three of my good guys. Careful with that Enlarge card! It's a doozy!
I've been meaning to try it out with card discard spells(memory loss, short perplexing ray)... especially in encounters with large groups. "You can empty your entire hand now, kthxbye".