Originally Posted by Stabbey
Originally Posted by vometia
I'm not from a D&D background, so I may not "get" it, but modifying the target score beforehand and then comparing the result of the dice-roll seems more straightforward to me...

I'm not particularly invested either way. I don't mind the reduction in target number as a way of dealing it, but I wouldn't care if they left the DC the same and added the modifiers after, either.

That's probably better, because there actually is a difference in effect, though. If a check has enough modifiers to it, the "target" could be be reduced as far down as 1, in which case you could pass it even with a natural 1, which by the rules is an automatic failure.

I actually encountered one check with a target of 1, and that was where I rolled my first natural 1 (in dialogue), and passed the check. It was the tutorial for using the Illithid tadpole, so the check was easy on purpose, but it still exposed a potential weakness.
This is actually incorrect, but a common misconception about 5e. Nat one's are not auto fails and nat 20's are not auto successes except in combat. Ability checks, saves and any roll other than attack rolls can succeed on a 1 if your modifier is high enough. Rules for rolling 1 or 20 covered page 194 PHB. This is a very common error by lots of players.