Official add-ons

The official add-ons are pwads that can be downloaded from Bethesda.net to be played with Doom Classic Unity port. Since console manufacturers do not usually allow players to use third-party content, the official add-ons system allows a selection of mods to be downloaded and played instead of being limited to the IWADs. Official add-ons are curated to ensure they are playable within the (raised) limits of Doom Classic, and to avoid potential copyright infringement in their content.

List of official add-ons
The two Final Doom IWADs are available as official add-ons for both The Ultimate Doom and Doom II. This effectively makes Final Doom free for all owners of either Classic Doom titles on Bethesda.net.
 * The Plutonia Experiment
 * TNT: Evilution

Ultimate Doom

 * Double Impact
 * SIGIL

Doom II

 * No Rest for the Living