Running and jumping

On the ground#

	Value
Run speed	220 ups
Sprint speed (W + sprint, no A/D, stamina > 10)	340 ups
Ground acceleration	5 (4.05 while sprinting, i.e. above 220)
Friction	4 (minimum control speed 100)
Step height	18 units, also in the air and while rising

Sprint only counts with W held and A/D released. Strafing on the ground is never sprinting.
Walking down stairs or a slope keeps you "on the ground" as long as the floor is within 64 units below, so you don't take off on small drops.

The jump#

Jump velocity 270 ups upward, horizontal speed unchanged. Apex 72.65 units (not the textbook 69.56, because velocity is snapped to whole numbers every command).
No auto-hop: jump must be released and pressed again. Holding it doesn't repeat.
Tired jump (stamina below 1500 or limping): 202.5 ups up, and the horizontal speed is halved. See stamina.md.
Costs stamina (1800 without a vest) unless g_stamina 2.

In the air: strafe jumping#

Air acceleration is 1: tiny. Speed comes from air strafing: hold A or D (with or without W) and turn the mouse the same way, so the wish direction stays a little ahead of your velocity. Each command adds a little speed.
The best angle depends on speed: the faster you go, the more sideways you look and the slower you turn (about 49° off your flight direction at 500 ups, 80° at 2000). The strafe HUD shows it.
Jumping again on the frame you land (bunny hop) keeps friction from slowing you. Since you have to re-press jump, timing is the skill.
Circle jump: turn while running into the first jump to start faster than 220.

The air angle: where you look vs where you fly — In the air you look away from where you fly. The best angle grows with speed (from the player guide).

Landing#

Landing faster than 200 ups downward freezes collision velocity changes for 250 ms (no wall slides change your speed then).
Fall damage above certain speeds (off with g_noDamage in jump mode).
Landing crouched above 300 ups starts a power slide (crouching.md).
Landing on another player bounces you up at 300 ups.

Overbounces#

A Quake 3 quirk that UrT keeps: at certain fall heights and speeds, the landing math misses the floor for a command and you bounce up instead of landing. Jump maps use them on purpose. The training tools find them.

What maps do with it#

Gaps sized for a strafe jump at a given speed: the line is the challenge.
Leets: the same jump with a farther exit for higher speeds.
Edges that catch you: an 18-unit step-up in mid-air can pull you onto a ledge, or stop you on a lip.