I'm using Ubuntu 9.10 Main. Wanted to try prboom which is a first person shooter game patterned after Doom. Installed it but when I try running it, I get the following error:

"jacatone@Dell ~ $ prboom

prboom v2.5.0 (http://prboom.sourceforge.net/)
I_SetAffinityMask: manual affinity mask is 1
M_LoadDefaults: Load system defaults.
default file: /home/jacatone/.prboom/prboom.cfg
IdentifyVersion: IWAD not found
prboom requires a doom data ("IWAD") file to use.
please install one, either freedoom or a package built
using game-data-packager."

Anyone know how I fix this? Thanks.

PRBoom is just the game engine; it does not come with all the data files necessary to play the actual game. To get those files you'll need to install either doom-wad-shareware (which has the data files from the shareware version of Doom) or freedoom (a free as in freedom and free as in price, replacement). Both packages are available in Ubuntu's repositories.

Edit: Forgot to mention, if you have a commercial copy of Doom or Doom 2, you can copy the *.wad files from that too.

Tried installing both data files mentioned and game seems like it's going to launch but closes instead. Below is the readout from my terminal.

"jacatone@Dell ~ $ prboom

prboom v2.5.0 (http://prboom.sourceforge.net/)
I_SetAffinityMask: manual affinity mask is 1
M_LoadDefaults: Load system defaults.
default file: /home/jacatone/.prboom/prboom.cfg
found /usr/share/games/doom/doom1.wad
IWAD found: /usr/share/games/doom/doom1.wad
PrBoom (built Nov 7 2009), playing: DOOM Shareware
PrBoom is released under the GNU General Public license v2.0.
You are welcome to redistribute it under certain conditions.
It comes with ABSOLUTELY NO WARRANTY. See the file COPYING for details.
V_Init: allocate screens.
found /usr/share/games/doom/prboom.wad
D_InitNetGame: Checking for network game.
W_Init: Init WADfiles.
adding /usr/share/games/doom/doom1.wad
adding /usr/share/games/doom/prboom.wad
W_InitCache

M_Init: Init miscellaneous info.
R_Init: Init DOOM refresh daemon -
R_LoadTrigTables: Endianness...ok.
R_InitData: Textures Flats Sprites
R_Init: R_InitPlanes R_InitLightTables R_InitSkyMap R_InitTranslationsTables R_InitPatches
P_Init: Init Playloop state.
I_Init: Setting up machine state.
I_InitSound: configured audio device with 1024 samples/slice
I_InitSound: sound module ready
S_Init: Setting up sound.
S_Init: default sfx volume 8
HU_Init: Setting up heads up display.
I_InitGraphics: 640x480
I_UpdateVideoMode: 640x480 (nofullscreen)
V_InitMode: using 8 bit video mode
I_SetRes: Using resolution 640x480
I_UpdateVideoMode: 0x60000000, SDL buffer, direct access
ST_Init: Init status bar.
G_DoPlayDemo: playing demo with doom/doom2 v1.9 compatibility
P_GetNodesVersion: using normal BSP nodes
I_SignalHandler: Exiting on signal: signal 8
I_ShutdownMusic: removing /tmp/prboom-music-fWyT8K
I_ShutdownSound:"

I'd guess you're running into the same bug as Launchpad bug #375498. Take a look at the comments on that page; hopefully they can provide some help.