Spike Ball

It looks like part of the dungeon and it is not. It follows ordinary spawn rules, appearing off screen and vanishing once you walk far enough away, which is the most useful thing to know about it: a corridor that looks impassable often clears if you back off and return. It shows up most in the stretches with slab walls behind them, so slow down when the background bricks change. It appears elsewhere far less often.

Nothing in your inventory damages it, so treat it as terrain and read the arc instead. Only the head hurts. The chain is harmless along its whole length, which puts the safe ground nearer the pivot than instinct suggests, and mining out the block it hangs from achieves nothing: it keeps swinging around empty air.

• Light the corridor first. It is dark enough that the first warning is usually the hit.
• Chain lengths vary between them, so the clearance you learned in one hallway does not transfer to the next.
• Unlike the spikes set into the dungeon floor, it does not cause bleeding, so the hit is the whole cost.