Falling damage is a great short example of how mechanical rules can shape player behavior. In systems like 3.5 D&D where falling damage is capped at 20d6 damage you reach a point where falling ceases to be an issue for characters. In some cases it can be preferable to their alternatives. Jump out the tower window and take the falling damage or face down a wizard monster with spells that target your bad saves? Not the best of choices but sometimes it's the only one you have. It doesn't even have to be the max damage. As long as the fall takes less than your maximum hit points, vigor points, or life points higher level players will fall off of high places rather than try to take a "safe" way down. Of course this leads to silly considerations, like high level fighters and barbarians falling from low orbit and walking away from the impact. So if you're building a RPG system and you don't want these sorts of shenanigans, keep your falling damage scaled to the stylings you desire for your system.