Exploit
Any way to gain an advantage that was not intended by the developers of a game is considered an exploit. In the JKA and JK2 there are a number of exploits in the saber damage system. Several of these exploits were corrected in Jedi Outcast Patch 1.03 when turning of the mouse was disabled for DFAs and backstabs.
Saber Exploits
Wiggle
By shaking your mouse left and right, you cause your lightsaber to move in and out of your opponent several times at high speed. This can cause an increase in the amount of damage your swing does.
Poke
By turning the mouse against the direction of a swing, jumping, crouching, etc, a player can cause his lightsaber to remain inside his opponent's hitbox for a longer time. This too, can cause an increase in the amount of damage your swing does.
Spin
By turning your mouse in the direction your saber is swinging, you cause it to hit your foes with more speed. This too, can cause an increase in the amount of damage your swing does.
Controversy
There is a great disagreement between the player-base over if exploits are allowed. Some consider it to be cheap, overpowered or unfair to use exploits, whilst others argue that any tactic which works should be allowed. It should also be noted that because of the fact that every mouse movement can effect the damage a swing does it is often hard to draw the line between when a player is or is not using an exploit, which creates a large grey area with this issue.