@Nick_ZOMZhey man quick question I’m sure you get a lot. Do spells w/ attack rolls crit on a nat 20 in D&D 5e? Yes; we specifically worded attack rolls and critical hits to work with spell attacks.
— Rodney Thompson (@wotc_rodney) February 18, 2015
Sage Advice: If you want to add gritty flavour to your criticals there’s a Lingering Injuries Table in the Dungeon Master Guide p.272, that describes different effect from a critical hit like losing an eye, broke ribs, horrible scar…