Some source ports change this behavior to something more consistent: for instance in ZDoom the Doom II secret exits outside of MAP15 and MAP31 merely lead to the same level as the normal exit. If such a level is not available, the player will be warped to MAP01: this effect is created by the secret level information not having been initialized. If the player uses a secret exit outside of MAP15 or MAP31, the next level will be the one that was last entered via an intermission screen.

MAP32: Grosse, a super secret level accessed from MAP31.īoth TNT: Evilution and The Plutonia Experiment, being originally designed as Doom II megawads, follow the same pattern.

MAP31: Wolfenstein, accessed from MAP15: Industrial Zone.

This allows to revisit the secret level an unlimited number of time, a quirk that permitted to demonstrate the armor percentage rollover bug. As a corollary, activating a secret exit within a secret level resets the level (following the usual intermission screen). Inversely, DARKHELL.WAD reaches E2M9 from E2M6, and loops back to it when exiting the secret level. Depending on the specific episode and level this occurs on, the player may end up either skipping several maps, repeating the level they just left, or being sent back to an earlier level.įor example, MOUNTAIN.WAD reaches E3M9 from E3M5, and continues on to E3M7, skipping E3M6 entirely. However, upon completing it, the player will be taken to the level immediately following the one they were meant to access it from. If the player activates a secret exit elsewhere than in one of the four aforementioned levels, the player will go to the secret level as usual. The actions of the secret level linedef types have been hard-coded into the engine.

E4M9: Fear, accessed from E4M2: Perfect Hatred.

E3M9: Warrens, accessed from E3M6: Mt.

E2M9: Fortress of Mystery, accessed from E2M5: Command Center.

E1M9: Military Base, accessed from E1M3: Toxin Refinery.

Doom 1 secret levels