Rolling a d20 and getting a “nat 20” or natural 20 is an a critical hit. A critical hit doubles the damage of the damage dice roll before the modifier.
Bob the paladin rolls a d20 and gets a natural 20 (critical hit!).
Bob then rolls a d8 for his weapon damage. He gets a 5. The 5 is doubled to 10. Bob then applies his +3 strength modifier to the total, for 13 damage all together.
Sidenote: Some DMs consider a natural 20 a hit even if that still doesn’t equal the creature’s armor class even with the attack modifier applied. For example, if a creature has an armor class of 30, some DMs would consider a nat 20 still a hit even if 20 + an attack modifier of 5 doesn’t equal or exceed the creature’s AC.
D&D Printout: Overview
Geek Dayton Reference Sheet
d20 Rules Overview
Reddit D&D Etiquette Discussion
Official Character Sheets
Character Sheet Explanation
Old Dungeon Master Website Text Explanation
YouTube Video on 5th e Character Creation (32 Min Long)
Spell Casting Explanation!
Spell Casting Info
Orc Pub D&D Generator
Dungeon Master’s Premade Character Library (Variety of Levels)
Wizards.com Level 1 Premade Characters (Level 1)
Name Generator (DM & Players)
Fantasy Name Generator
Note: I wouldn’t put too much faith in how much this coincides with D&D and the other realms listed, but it can help if you’re not in a creative mood.
Alignment from Easy Damus
Final Fantasy D&D Classes
Homebrew Final Fantasy Classes