Quake

Hunting tip from David Holley
When ever you are fighting a Fiend try to make it fall into the water. this will cause it to instantly die.

Nightmare Mode from David Holley
To get nightmare mode go to the place where you choose the episode you would like to start playing. Go the fourth episode and fall down the pool of water. While you are singking strafe left and you will land on a ledge. There is a doorway on the ledge. go inside and you will find a slipgate that says nightmare. This allows you to play in nightmare mode (a harder dificulty).

Jevons Controls from David Everly
During play, pause and enter the option menu. Highlight "Customize Control" and press R,R,L,R,X,Y,Z,X,Y,Z in one swift motion until you see a fant message appear behind the text from the option menu. Jevons Controls should now be activated.

Gameshark Codes from MRE
Master Code: F6017918 C305 / B6002800 0000
INVINCIBLE: 16074A52 00FF
INFINITE ARMOR: 16074A5A 00FF
INFINITE SHOTGUN AMMO: 16074A66 00FF / 16074A6A 00FF
INFINITE NAILGUN AMMO: 16074A6E 00FF / 16074A72 00FF
INFINITE ROCKETS/GRENADES: 16074A76 00FF / 16074A7A 00FF
INFINITE THUNDERBOLT: 16074A7E 00FF
QUAD DAMAGE ALWAYS ON: 16074C52 02F7

Wierd Code from R13@rocketmail.com
Let the game sit untill it shows the Lobotomy outhouse, when it shows it, Hold L and R and press anything like x,y,z,a,b,c it should make weird farting noises.

All Runes from J.Marcias
stand in the Area in "The Hose of Cthon" where the first Rune was located and pause the game highlight Custome Controls from optionsand press R,Z,L,X,Y,L,R.

Stronger Weapons from J.Marcias
Pause the game highlight "Auto Tracking" from options and press R,R,L,R,X,Y,Z,X,Y,Z Paul Mode (Invincibilty) Pause game highlight "Custom Controls"and press R,L,X,Y,Z,R,L,X,Y,Z

Zero-G mode from J.Marcias
Pause game highlight LookSpring from options and press R,R,L,R.X,Y,Z,X,Y,Z

View Map from J.Marcias
Pause Game highlight Custom Controls from options menu and press L,R,L,R,Z,Y,X,X,Y,Z

Full Health from J.Marcias
Pause Game enter Options Menu and highlight Custom Controls and press R,Y,L,Y,X,Y,Z,X,Y.

Easy Mode from J.Marcias
Pause Game highlight Music Volume form Options Menu abd press R,L,X,Y,Z,R,L,X,Y,Z

Hard Mode from J.Marcias
Same as above instead push R,X,L,Z,L,,R,Y,L,R,Y.