Activate Cheats
1. Create a copy of your single player desktop shortcut.
2. Right-click on it and select "properties".
3. In the "Target" field, add the following to the very end
   (outside the quotes): +set sv_cheats 1 
4. Click OK.
5. Launch the game using that shortcut. 

     Once  you're in the game, you should be able to use the following
cheat codes (hit the "~" key to bring down the console, then type them
in).  Or  if this doesn't work, start the game, enter the console, and
type: /killserver. This will take you back to the main menu but cheats
will be activated.

Code Result 
/god God Mode 
/notarget Enemies Do Not Attack 
/noclip No Clipping 
/give all All Weapons and Ammo 
/give armor Give Armor 
/give health Give Health 
/give stamina Give Stamina 
/give ammo Give Ammo 
/give snooper rifle Give Osa M1 Night Rifle 
/give sniper scope Give Mauser + Scope 
/give flamethrower Give Supercharged Ronson 
/nofatigue Unlimited Stamina 
/kill Suicide 
/cg_uselessnostalgia 1 Original Wolfenstein Interface 
/give # Give Item # (See List) 
/spdevmap mapname Switch to Map "mapname" (See List) 


Special Note
     Some  people  have  experienced problems activating the cheats as
listed  above. Here is an alternate to try if they are not working for
you.

1. Add " +set sv_cheats 1" to the target line of the shortcut,
   as shown above.
2. Add a blank "user.cfg" file to the folder labeled "Main",
   in the game folder to "Return to Castle Wolfenstein".
3. Type one line in that "user.cfg" file: set sv_cheats 1
4. Enter codes as shown above. 

Special Note #2
     Some  people  have  not  been  able to use the cheats unless they
first  load  a  saved game. New players can start, save, then load the
save and the cheats should work.

Cheat Help:

1.  Create  a  copy of your single player desktop shortcut. (rename it
e.g., Wolf-Cheat)
2. Right-click on it and select "properties"
3.  In  the "Target" field, add the following to the very end (outside
the quotes): +set sv_cheats 1
4. Click OK.
5. Launch the game using that shortcut. 

If it doesn't work...
1. Start a new game in normal mode.
2. After the cut scenes (you can press esc to skip the cut scenes) you
save the game at the starting point.
3. Quit the game, return to windows or the main menu.
4. Load the game you just saved.
5.  Once loaded try to use the console again and all the cheats should
work.

Notes:
1.  The  steps above will work if you saved your game using the edited
shortcut  (e.g.,  Wolf-Cheat);  previous  save  games  from  non-cheat
enabled shortcuts don't seem to work.
2.  Cheats  don't work on the hardest difficulty level, it should work
on easy but I've only used normal the hardest difficulty level so far.

Give List
     Use these with the /give cheat listed above.

panzerfaust
venom = gives Venom Chaingun
tesla gun
flak jacket
armor
dynamite
thompson
mp42
mauser rifle
flamethrower
sten
fg42 paratroop rifle
grenade
colt 45
large health
medium health
9mm
12.7mm
7.92mm
.30cal
.45cal
cell 

Map Names
     Used with the /spdevmap command.

escape1
escape2
tram
village1
crypt1
crypt2
church
boss1
forest
rocket
baseout
assault
sfm
factory
trainyard
swf
norway
xlabs
boss2
dam
village2
chateau
dark
dig
castle
end

Move Faster:
     /g_speed xxx - where xxx is normally 320 (higher numbers make you
walk/run/sprint faster, lower numbers make you go slower); max. 999.