Searing Smite

Level & School
1st-level evocation
Casting Time
Bonus action, which you take immediately after hitting a target with a melee weapon or an unarmed strike
Range
Self
Components
V
Duration
1 minute
Classes
Paladin

As you hit the target, it takes an extra 1d6 Fire damage from the attack. At the start of each of its turns until the spell ends, the target takes 1d6 Fire damage and then makes a Constitution saving throw. On a failed save, the spell continues. On a successful save, the spell ends.

Using a Higher-Level Spell Slot. All the damage increases by 1d6 for each spell slot level above 1.

Level & School
1st-level evocation
Casting Time
Bonus action
Range
Self
Components
V
Duration
Concentration, 1 minute
Classes
Paladin

The next time you hit a creature with a melee weapon attack during the spell’s duration, your weapon flares with white-hot intensity, and the attack deals an extra 1d6 fire damage to the target and causes the target to ignite in flames.

At the start of each of its turns until the spell ends, the target must make a Constitution saving throw. On a failed save, it takes 1d6 fire damage. On a successful save, the spells ends. If the target or a creature within 5 feet of it uses an action to put out the flames, or if some other effect douses the flames (such as the target being submerged in water), the spell ends.

Using a Higher-Level Spell Slot. When you cast this spell using a spell slot of 2nd level or higher, the initial extra damage dealt by the attack increases by 1d6 for each slot above 1st.

Searing Smite 5.5e 2024 vs. 5e 2014 edition differences

The 2024 version removes the ignition effect, requiring the target to take damage before saving, and ends the spell on a successful save rather than on a failed one. It also states that damage increases with higher spell slots, but clarifies that all damage increases by 1d6 per slot above 1st.