Hex

1st-Level Enchantment Spell (Warlock)

Casting Time: Bonus Action
Range: 90 feet
Components: V, S, M (the petrified eye of a newt)
Duration: 1 hour

You place a curse on a creature that you can see within range. Until the spell ends, you deal an extra 1d6 Necrotic damage to the target whenever you hit it with an attack roll. Also, choose one ability when you cast the spell. The target has

If you have Disadvantage on a D20 Test, roll two d20s and use the lower roll. A roll can't be affected by more than one Disadvantage, and Advantage and Disadvantage on the same roll cancel each other. See also D20 Tests.

on ability checks made with the chosen ability.

If the target drops to 0

Hit Points (HP) are a measure of how difficult it is to kill or destroy a creature or an object. Damage reduces Hit Points, and healing restores them. You can't have more Hit Points than your Hit Point maximum, and you can't have less than 0. See also Breaking Objects and Damage and Healing.

before this spell ends, you can take a

A Bonus Action is a special action that you can take on the same turn that you take an action. You can't take more than one Bonus Action on a turn, and you have a Bonus Action to take only if a rule explicitly says so. See also Actions.

on a later turn to curse a new creature.

At Higher Levels: Your

Some spells and other effects require Concentration to remain active, as specified in their descriptions. If the effect's creator loses Concentration, the effect ends. If the effect has a maximum duration, the effect's description specifies how long the creator can concentrate on it: up to 1 minute, 1 hour, or some other duration. The creator can end Concentration at any time (no action required). The following factors break Concentration.

Another Concentration Effect. You lose Concentra ... [more]

can last longer with a spell slot of level 2 (up to 4 hours), 3-4 (up to 8 hours), or 5+ (24 hours).

Source: Player's Handbook, p. 285