For Die Hard with a Vengeance
E, O, X, O, E, L, X, D, L affects other cars once they are hit.
For Die Harder
down, A, right, E god mode
left, A, right, down keeps aim from automatically shifting
down, E, A, down skeleton mode
For Die Hard
right, E, E, down fat mode
right, up, down, down, E, right unlimited weapons
Other Codes
In any of the three games, hit Esc to pause the game. When the code is typed in correctly, the game should unpause.
For Die Hard with a Vengeance
left, O, up, down, E, right unlimited lives.
For Die Harder
right, up, down, E change guns (repeat as necessary)
right, up, down, E, E god mode
right, E, left, O, A, down, E extra missiles and grenades
Regular Codes
In any of the three games press Esc to pause. Press (and hold) the R and 2 keys. Keep them down! Right and left stands for right arrow key, left arrow key, and so on. When the code is typed in correctly, release the R and 2 keys, and the game should unpause.