In shooter games, rocket jumping is the technique of using the knockback of an explosive weapon, most often a rocket launcher, to launch the shooter into the air. The aim of this technique is to reach heights and distances that standard character movement cannot achieve. Although the origin of rocket jumping is unclear, its usage was popularized by Quake. Rocket jumping is used often in competitive play, where it can allow the player to gain quick bursts of speed, reach normally unobtainable heights, secure positional advantages, or in speedrunning. However, a potential consequence of rocket jumping is that it can injure the player, either from the blast or from fall damage. This effect makes the technique less useful in games where the damage from the blast and/or fall is high, or where health is difficult to replenish. Rocket jumping from standing is impractical in real life, and would be certainly fatal if attempted. However, ejection seats from an aircraft are, in effect, a combination of a seated rocket jump and a parachute. In the Quake series While using explosives to propel oneself was first seen in Doom, the modern technique became a core mechanic in Quake. By exploiting the physics of the Quake engine, many advanced movement techniques were spawned such as circle jumping, strafing, bunny hopping, and explosive jumping. Rocket jumping was kept as an intentional mechanic for the leading games in the Quake series. In Quake III: Arena some of the computer-controlled opponents use rocket jumps. Forms Rocket jumping has appeared in several games in a variety of forms, sometimes as a form of emergent gameplay. Horizontal A horizontal form of rocket jumping appears in Doom (1993), where it is used to reach the secret exit in E3M6. Vertical The first games to feature vertical rocket jumping were Bungie's Marathon and 3D Realms' Rise of the Triad, which were both released on the same day. It was featured the same year on The Outfoxies. Rocket jumping became very popular in the original Quake (1996), and was used as an advanced technique for deathmatch play as well as for the Quake done Quick series. In the game Team Fortress 2 (2007), the Soldier class can use his rockets to rocket jump. This is an intentional feature with several mechanics associated with it. The game features numerous unlockable weapons with attributes that only affect rocket jumping or only apply while