Light

Lights up dark places so monsters stop spawning in them. Level 1 puts a single lit circle on the block you aim at.

From level 2 up you do not need to aim at a block, and the spell keeps working after the cast: lit circles spread out from where you cast it through the open space in the direction you are facing, one at a time, landing wherever it is still dark. Turn around and the spread follows your new facing, so you can light a cave by walking through it. Places that are already lit are skipped.

The table shows how many circles each level can place. You pay once, when you cast; the lit circles cost nothing to keep.