Double jump making a return in a q2/cpma/wsw style could be nice. In these titles when one jump is followed quickly by another – for example jumping up two crates or up a set of stairs – the player receives a vertical boost roughly equivalent to the height of two jumps on their second jump, giving them a total jump height of around three jump. Movement wise there is not much on the vertical outside of lift jumps and this would open it up. It is much simpler for mappers to police who are worried about scale (avoid ledges players can jump+jump up) and adds some vertical movement options. Would probably be nice chaining a wall dodge off this vertical boost. You can jump up those four crates individually or if your timing is good you can do two jumps timed well and gain additional height off the second crate and land on the top of the pile.
While it would give more height than the traditional ut double jump it is also more constrained by map geometry as well as how it gives the bonus. For example it is quite limited and gives a heavy upwards boost, giving players nice predictable flight paths.
Reflex has it, at the start of this video and an example of a “triple jump” using the same idea around 1:10.
If you wanted to add a little, make the second jump receive a similar amount of inertia to a dodge, but in the upwards direction, making the player move faster.
To me this mechanic has always stood out as one of the few quake mechanics that would suit ut rather than strafe jumping or bunnyhopping.
FPS