I've been trying to hurt dwarves, for my healthcare dwarf to practice on, by building a retracting bridge, stationing a squad there, and then retracting the bridge.
If the fall is just 1z, i.e. the bridge is on the level right above the ground, the dwarves just get stunned and not damaged. If the fall is 2z, they die every time.
How can I reliably hurt dwarves without killing them?