Hex

1st-Level Enchantment
Casting Time: 1 bonus action
Range: 90 feet
Components: VSM (the petrified eye of a newt)
Duration: (C) 1 hour

You place a curse on a creature that you can see within range. Until the spell ends, you can deal an extra 1d8 necrotic damage to the target when you hit it with an attack roll. You can deal this extra damage only once per turn. Also, choose one of the six abilities whenever you cast the spell. The target has Disadvantage on ability checks made with the chosen ability.
If the target drops to 0 hit points before this spell ends, you can use a bonus action on a subsequent turn of yours to curse a new creature.
A remove curse spell cast on the target ends this spell early.

At Higher Levels. When you cast this spell using a spell slot of 3rd or 4th level, you can maintain your concentration on the spell for up to 8 hours, and the extra damage increases to 2d8. When you use a spell slot of 5th level or higher, you can maintain your concentration on the spell for up to 24 hours, and the extra damage increases to 3d8.

Source: PHB 251

Changelog

Increased damage dice to d8s.