You create a bonfire on ground that you can see within range. Until the spells end, the bonfire fills a 5-foot cube. Any creature in the bonfire’s space when you cast the spell must succeed on a Dexterity saving throw or take 1d8 fire damage. A creature must also make the saving throw when it enters the bonfire’s space for the first time on a turn or ends its turn there.

The spell’s damage increases by 1d8 when you reach 5th level (2d8), 11th level (3d8), and 17th level (4d8).

My Comments: I don’t know why, but I had always skipped over this cantrip and never bothered to read it. Maybe I thought it sounded too much like a party trick for the beach. Turns out, it’s a tidy little fire damage spell. Not only is it a flash of d8 damage on your turn, assuming they don’t make save, but the fire continues to burn in that 5″ area, so if you can trap an enemy there or drop it in a choke point, it can continue to do damage for a full minute and in D&D combat time, a minute is a very long time.

Mind you, it does require concentration which is a pricey commodity later on it a caster’s career.

Outside of combat, there are many reasons one might want to randomly start a nice bonfire. For example, you’ve decided to burn down the house with the vampires in it rather than going in. Or, maybe you just want to keep warm and forgot your kindling…

Upside, it’s a mini-fireball that sticks around at cantrip level.
The downside, it requires concentration.
The trade-off- no to-hit required, but the target does get a Dex save to avoid damage completely.