A Hammer Jump is a higher than normal jump using the Impact Hammer weapon.
The Impact Hammer adds a little extra upward force to the upward motion resulting in a higher jump. This jump will cause your player to take some damage.
Some maps have weapons and other objects on boxes or other obstacles which require a weapon assisted jump to get to (e.g. the damage amp in DM-Turbine and the redeemer in DM-Barricade if you don't have jump boots on). This makes the object harder to get because it takes more time to do a weapon assisted jump and also because damage is taken by the player doing the jump.
To do a Hammer jump:
- Use the Impact Hammer weapon.
- Point the weapon directly downward.
- Fully charge the impact hammer by holding the left mouse button down.
- Immediately release left mouse button to release the Impact Hammer's stored energy.
Note: In team games, this effect can also be produced by hammering a teamate who jumps up in front of you when team damage is off. The jump produced is higher than a normal self-induced hammer jump. The technique is called "boosting" and is most commonly used in Assault games, where it is used to propell players over walls and other obstacles, usually to the generally agreed upon detriment to game play, although some custom maps incorporate this type of movement and even require it.
ZxAnPhOrIaN: I'm going to create a Hammer Jump obstacle course for newbies to train in!
Tarquin: Impact Jump Metrics from General Scale and Dimensions