An IWAD - short for Internal WAD - is the main resource file for a Doom-engine game, containing all the game's original sounds, levels, and graphics. ZDoom needs an IWAD file in order to play; without one the ZDoom engine has no game data to use.
- Some file names are links to a page on the where you will find checksums for known versions of the concerned file.
- Some files have conflicting names; ZDoom provides you with possible aliases. Note that an IWAD is actually identified by its content rather than its name.
|Game||Name||File name||File aliases||Notes and download links|
|Doom (Shareware)||Free download: Doom shareware at Doomworld/idgames|
|Doom (Registered)||Commercial game|
|Ultimate Doom||doomu.wad||Commercial game|
|Doom "BFG Edition"||bfgdoom.wad, doombfg.wad||Commercial game included with(New from )|
|"Ultimate" Freedoom||doom.wad||freedoomu.wad||Free download: official site|
|Doom II||Commercial game|
|Doom II "BFG Edition"||bfgdoom2.wad, doom2bfg.wad||Commercial game included with, also loads (New from )|
|Final Doom — TNT: Evilution||Commercial game|
|Final Doom — The Plutonia Experiment||Commercial game|
|FreeDM||freedm.wad||Free download: official site|
|Complete Freedoom||doom2.wad||freedoom.wad||Free download: official site|
|French Doom II||doom2f.wad||Commercial game, patch available at Doomworld/idgames|
|Heretic (Shareware)||Free download: Heretic shareware at Doomworld/idgames|
|Heretic (Registered or Commercial)||Commercial game|
|Blasphemer||heretic.wad||blasphem.wad, blasphemer.wad||Free download: official site|
|Hexen (Demo)||hexdemo.wad, hexendemo.wad||Free download: Hexen demo at Doomworld/idgames|
|Hexen (Full)||Commercial game|
|Hexen: Deakhkings of the Dark Citadel||Commercial game, requires Hexen|
|Strife (Teaser)||Free download: Strife teaser at Doomworld/idgames|
|Strife (Full)||strife.wad||Commercial game no longer sold, also loads|
|Chex Quest||Commercial game no longer sold|
|Chex Quest 3||Free download: official site|
|Action Doom 2: Urban Brawl||Free download: official site|
|Harmony v1.1||Free download: official site|
|Hacx v1.2||Free download: official site|
|Hacx v2.0||hacx.wad||hacx2.wad||Free download: WIP download thread|
ZDoom will detect any of those present in its search path and let you choose at startup which game to play (if it doesn't, see the FAQ). In addition to them, some "total conversion"-type mods, such as Wolfenstein 3D TC, can be played as their own IWAD; however since they are not detected as such by ZDoom, you need to use the -iwad command line parameter.
In order to play a custom level designed for any of the above games you have to have that particular game's full IWAD (loading PWAD with shareware, demo or teaser versions is disabled). If you do not have the necessary IWAD, or if you have an old, unpatched version of the IWAD in question, you will get an error message on startup. (But often old versions are accepted too.)
The IWAD file(s) should be placed into the same directory as the ZDoom executable. You may also configure other directories for ZDoom to search in the zdoom.ini file. On Linux, the directories $HOME/.zdoom and /usr/local/share are checked by default. Finally, if you have bought Ultimate Doom, Doom II, Final Doom, Heretic, or Hexen from Steam, ZDoom is able to find the IWADs directly in the Steam folder and you do not need to move or copy them to ZDoom's folder.
As noted aboved, some IWADs can be downloaded freely; however most "full" games are not and must be bought from one of the following sources:
- Id Software Store
- This store offers downloadable versions of Ultimate Doom, Doom II: Hell on Earth, Final Doom, Heretic: Shadow of the Serpent Riders and Hexen: Beyond Heretic.
- Note: The version of Hexen: Beyond Heretic available on the Id Store is not patched. You need to download and apply the Hexen 1.1 patch first.
- This store offers downloadable versions of Ultimate Doom, Doom II: Hell on Earth, Final Doom, Heretic: Shadow of the Serpent Riders, Hexen: Beyond Heretic and Hexen: Deathkings of the Dark Citadel; as well as the Master Levels for Doom II which is a set of PWAD, not an IWAD.
- Warning: following the release of , the Master Levels are no longer available to purchase, although those who have already purchased them can still download them.
- Note: The version of Hexen: Death Kings available on Steam is not patched. You need to download and apply the Death Kings 1.1 patch first. (The "readme.txt" file it tries to patch has been renamed readme-dk.txt by Steam, but is not important.) All other IWADs from Steam are fully patched.
- Amazon.com, eBay.com, etc.
- Second-hand copies of the original games can be found on such sites. While less reliable than the official Id Software and Steam stores, they are the only remaining sources for legitimate copies of Strife: Quest for the Sigil and the original Chex Quest.
- Flea markets, used-games bins in brick-and-mortar stores, etc.
- It's mostly a matter of luck, but they can still sometimes be found this way.