Log: *** zaps Skag *** reacts! *** inducts sparks Slag took 5 Arcane damage. "Zap" is Magic Arcane, that does 4 Arcane Damage. "Spark Inductor" reads, "Add 1 damage to any Electrical Attack..." I have spells that are both "Magic Arcane" and "Magic Electric", so I'm assuming there's a difference between those two types.
There should be a difference, yes. But Big Zap does 5 Arcane damage just fine. Are you sure you didn't play the "big" one?
I'm sure. I took a screenshot of my battle log, but unfortunately it doesn't tell me which Zap it was. Regardless, do you see the "inducts sparks" reaction after each and every spell you're casting?
Spark inductor reacts for arcane as well, but with the effect of making the attack harder to block - so it triggering in the log is not incorrect, due to that.