Falling damage has differed slightly through the various versions of the D&D game and clones. The most common damage taken seems to be 1d6 per 10 feet fallen. In a recent version that changed to 1d10 damage per 10 feet.
Some versions apply modifiers for deliberately jumping, landing in water or softer substances, having the tumbling skill, etc.
In Labyrinth Lord for example the first mention I recall seeing about falling damage is in the description of the consequences of falling into a pit trap = 1d6 per 10 feet fallen.
In honor of the recent damage escalation discussion . . .
What if we tried modifying the dice used?
Perhaps the first 10 feet was 1d4, second 10 feet 1d6, third 1d8, etc? Then you could shift the dice to reflect the modifiers. For example, deliberate jump makes the escalation of die type begin one step later. The first 10 feet remains 1d4 then the second becomes 1d4, then 1d6, 1d8. Say the character deliberately jumped into water it could be 1d4, 1d4, 1d4 covering the first 30 feet and then begin to escalate 1d6, 1d8, etc.
Would this be worth experimenting with or should it be kept simple at 1d6 per 10 feet and rule on the fly if some is non-lethal damage?
What other systems for modeling falling damage have you seen in fantasy rpgs?