[MC-312495] Player fall distance is off by one

When calculating fall damage, player fall distance seems to be off by one.

To reproduce:

Default attributes, safe_fall_distance = 3.0, fall_damage_multiplier = 1.0
Run /tp ~ ~3.0 ~, no damage as expected
Run /tp ~ ~3.5 ~, still no damage when it should be 1HP
Run /tp ~ ~3.9 ~, still no damage
Run /tp ~ ~4.0 ~, 1HP of damage when it should be 2

The same can be seen if e.g. safe_fall_distance is set to 2.0, you only start taking damage after you fall 3 blocks.

Was not an issue before 1.21.5.

Comments 1

RoccoDev 2026-10-10T20:04:28Z

Code analysis for the 26.3 client:

It appears that in 1.21.5 the formula in LivingEntity#calculateFallDamage was changed to round the final value down instead of up. Perhaps it was intentional, but as it stands the safe_fall_distance attribute is somewhat misleading.