From Team Fortress Wiki
Fall damage is a type of damage that is only applied when a player falls from a certain height.
Fall damage is calculated as being proportional to the vertical distance traveled by the player before they hit a horizontal surface. As such, the greater the distance from the ground at the start of the drop, the greater the amount of damage given. Fall damage is accompanied by a distinct 'bone crunching' sound that serves to indicate the player has been injured from the fall. Other players will also see a blood particle effect from the damaged player.
Players that attempt to crouch during the fall will inadvertently suffer more damage than if they had remained standing upright. This is because crouching results in the player's bounding box becoming smaller and therefore higher off the ground. This creates a greater height distance between the character and the ground. Conversely, a player who crouches just before leaving a ledge surface who then proceeds to stand in mid-air will have shortened his potential fall distance.
It is important to note that fall damage can be negated by utilizing abilities such as double jumping, sticky jumping or rocket jumping near the end of the fall, as this essentially resets the vertical travel distance. The splash damage dealt by explosives used to cancel the fall, however, could result in delivering further damage to the player. No such problem exists with training weapons such as the Rocket Jumper.
Certain map areas are intentionally affixed to instantly kill the player with severe fall damage, regardless of health status at the time.
Deaths resulting from fall damage generally occur when a wounded player takes a large leap and miscalculates the risk. As such, upon reaching a surface and receiving fall damage, the player's class will ragdoll with the accompanying bone crunching sound. Players can also use fall damage to their advantage, as they can push the enemy off the edge and earn a kill, without having to go into direct combat. This is most useful to Pyros, who can ignite their enemies and airblast them off an edge or into another environmental hazard.
The Soldier can also use fall damage offensively, but in a very different fashion. While wearing the Mantreads, a player can attempt to land on an opposing player after falling from a height sufficient to inflict fall damage. If they succeed, the resulting fall damage is tripled, and inflicted on the opponent the player landed on. They will receive no self fall damage if they hit a player, but still will take damage if hitting a surface.
Note: damage values are approximate and have been determined by community testing.
Originally sourced from this document.
| Fall Classic|
Cause an environmental death or suicide using the Force-A-Nature's knockback.
| Medical Intervention|
Save a falling teammate from dying on impact.