I've always thought falling rules were a little lacklustre when it comes to being a threat to higher level parties. The cap at 20d6 seems to low for a 200+ft fall so I've added a little bit.

When you fall from a height of 10ft or more you suffer 1d6 bludgeoning damage/10ft fell at the end of the fall. If you fall further than 30ft then the damage dice changes from d6's to d12s /10ft fallen and caps at a maximum of 50d12(500ft). For example, a 30 ft. fall is 10(3d6) damage, however a 50ft fall is 32(5d12) damage. This makes shorter, more common falls more survivable while longer falls prove a significant threat.

This is based on the fact that most falls become deadly beyond 25ft to your average person, but because your players are heroes and have that protagonist's luck on their side, they should find these shorter falls an inconvenience but not life threatening but large drops are still an imminent threat.

In short: 

1d6/10ft up to a 30ft of falling,

Beyond 30ft damage changes to 1d12/10ft capping at 50d12 (flex tape won't fix that)

What do you think? Good/bad idea? Too cruel? Too easy to be cheesed by players? Too complicated?

One thing is that it doesn't make shorter falls more survivable than they currently are, it just makes higher falls more dangerous than before!

It seems to achieve what you wanted, but I wonder if it's any more representative of falling than the current system was!

Also, expect every fight to involve the PC's asking if there's a 30ft.+ drop nearby to deal damage to the enemy!

See, this is what happens when I get fixated on someone saying "falling rules are a bit lacklustre". I hope you're happy!

I've started my own thread on it to not steal yours, but it's your fault I wrote it! XD