Critical hits only hit regardless of modifiers or the target's AC, but there are other things that can cause an attack to miss. For example, if the target is hiding and the character must guess their location, if they guess wrong then their attack will miss automatically even if they roll a nat 20.

Do crits auto hit DnD 5e?

To put it simply, critical hits in DnD 5e mean you automatically hit your target (regardless of their armor class) and double the number of damage dice your roll. The die type changes based on the weapon. ... Now, usually, that's all crits do; automatically hit and double damage dice.

Does a nat 20 always hit?

Automatic hit/success

In several editions of the D&D rules, a natural 20 is an automatic hit on an attack roll, regardless of the opponent's armor class. ... Contrary to popular belief, a natural 20 is not an automatic success on skill checks or ability checks in D&D 3rd, 4th, or 5th edition.