Preface: I realize this is a fairly broad question that likely doesn't have a comprehensive answer, but I'm looking for the best you're willing to put the time into explaining; What is the determining verbiage for whether or not a spell, with multiple effects, that has one of the targets of it's effects made invalid before resolution, resolves? I.e, if the target of my slip through space dies, do I get a card? If so, is it because of the line break? Because of the period? Would a comma work?
It has nothing to do with punctuation or line breaks.
A spell with a single target will be countered and thus have none of its effects happen if its target is no longer legal when the spell tries to resolve.
For example, you cast Slip Through Space targeting your creature, but that creature dies to a Fiery Temper before Slip Through Space can resolve. When Slip Through Space goes to resolve, it sees that none of its targets are legal so it’s countered instead of resolving. You don’t get to draw a card.
A spell with multiple targets will be countered this way only if all of its targets are no longer legal when it resolves. If any of the targets are still legal, the spell will resolve and do as much as it can, though it won’t be able to affect the illegal targets.
For example, you cast Expose Evil targeting two of your opponent’s creatures. One of the targets is a Wild-Field Scarecrow, which your opponent sacrifices to activate its ability before Expose Evil resolves. When Expose Evil goes to resolve, it only has one legal target, but because it still has a legal target left, it resolves and does as much as it can. The remaining target becomes tapped and you investigate.