Bunny-hopping is the most basic method of fast movement in which player is jumping repeatedly instead of running in order to move faster. Strafe-jumping (SJ) is a technique necessary to complete the majority of "DeFRaG" maps, and is considered to be the most fundamental technique in trick jumping. It is only possible because of a specificity of the game's physics unintentionally allowing moving vectors to add up to greater acceleration. Basically, no matter if the player's character is moving on the ground (running) or is airborne (jumping), the game engine always strives to limit its speed. However, already in the original "Quake" it was discovered that by non-trivial timed sequences of striking the direction keys (involving moving sideways, "strafing" in gamer language) and movements of the mouse, this limitation of speed could be overcome. As the "Quake" engines are the basis of many games, the possibility of strafe jumping is existing within other games, too. But "Q3A"'s trickjumping community developed several distinct sub-techniques including single-beat strafe-jumping, single-beat strafe-jumping with airchange, double-beat strafe-jumping, half-beat strafe-jumping, and inverted strafe-jumping. The "DeFRaG" mod includes a helping tool, the Camping Gaz Head-Up Display (CGazHUD), which provides conveniently graphically formatted real-time feedback on acceleration and angles involved.