A “spell effect” is a type of thing in mtg. Its saying the enchantment affects the spell itself not the effect of the spell. I can’t think of an example where that would make a difference but if there is an MTG player will exploit it.
The closest thing I can think of is some copy spells append wording and if it appends multiple lines of text to another spell “effect” wouldn’t stop it in certain situations that “affect” would.
The card says a spell’s effects can’t affect you.
A “spell effect” is a type of thing in mtg. Its saying the enchantment affects the spell itself not the effect of the spell. I can’t think of an example where that would make a difference but if there is an MTG player will exploit it.
The closest thing I can think of is some copy spells append wording and if it appends multiple lines of text to another spell “effect” wouldn’t stop it in certain situations that “affect” would.