How to play or start wads

How to play or start PWADS
You need a copy of registered Doom, Ultimate Doom or Doom 2, and a sourceport if wanted; for example, Zdoom, Doom Legacy or ZDaemon. You'll also need a PWAD for your version of DOOM.

Original DOS doom
The same commandline parameters apply for both DOOM and DOOM 2.

Place the PWAD in your Doom directory (usually C:\DOOM\). For example, we'll use DOOM with the PWAD "DBS.wad". After that, you can start Doom with the PWAD by using this on the commandline: doom.exe -file DBS.wad This will start your copy of DOOM with the DBS.wad patch applied.

Sourceports/frontends
Most frontends will have an option for starting a PWAD when you launch the game.

In DOOM Legacy: Start Doom in Single Map mode, and select a PWAD in the "Additional Files" area.

In ZDaemon: Start a local game and select the PWAD from there.

In ZDoom: Drag the PWAD over the ZDoom.exe file, and it should auto load.

There are plenty of other frontends to use, and PWAD loading should be simple to do.