the most dangerous things in jumping off cliffs and bridges is what you are landing into. I know people who have hit the bottom hard, when previously had jumped without even hitting it. rivers are sketchier because it's hard to know where you are when you dive down to check, or if you check with a weight, because of the current. Also some cliffs you must hit a narrow spot or clear a certain distance or, have a sketchy climb up, or not much of a good takeoff zone. All those factors are the big killers.
For just pure height though, I would say anything over 15m is where I would start sticking with tricks I know I am going to land pretty well, because the likely consequence of fucking up goes from pain, to hurting myself.
The biggest cliff I ever jumped of was probably around 25m and although it was a pretty safe jump, the height made it dangerous IMO. Like if you backslap from 25m you are hitting the water around 80km/h. That could fuck you up.
you can get a lot more airtime off a nice jump or ropeswing than you can with a big cliff anyways and the hangtime feels better than just falling for 2 seconds. I mean this video has about the same amount of airtime as a 25m (80') cliff, if not a little more, but I hit the water with MUCH less force than I would have if I tried this off a cliff. And this one still knocked the wind out of me real good haha.
