This tiefling warlock at level 5 from WotC's site has a dagger attack I can't figure out:
Dagger. Melee Weapon Attack:
+6 to hit, reach 5 ft. or range 20/60 ft., one target.
Hit: 1d4 + 2 piercing damage.
First, I can't figure out why the dagger does 1d4 + 2 piercing damage. Looking at page 149 of the Player's Handbook, the dagger only shows that it is 1d4 piercing, nothing more, so I really don't know where the +2 piercing damage comes from.
Second, nowhere in the weapon's listing says how to figure the attack bonus. Where in the Player's Handbook does that +5 to hit come from?
I've seen a question here which states that for ranged weapons attacks the attack bonus is calculated as Dexterity modifier + proficiency bonus, whereas melee attacks it is strength + proficiency bonus, but on the 5th-level Tiefling Warlock's sheet you can see his stats don't reflect that:
Str: 8 (-1)
Dex: 15 (+2)
Con: 14 (+2)
Int: 13 (+1)
Wis: 10 (0)
Cha: 18 (+4)
With those stats the melee attack bonus for a dagger should be −1 (Strength modifier) + 3 (proficiency bonus) = +2.
But it isn't — it is +6. Why?