Is the current account on how Nightmare was added to Doom accurate?

[Individualised]

It's said that Nightmare was first thought up of after Doom's release when fans asked for a harder difficulty, and implemented as a joke. The May, 22nd, 1993 prototype references 5th and 6th skills called "sk_deadly" and "sk_deadlybaby" (presumably Nightmare without extra ammo and Nightmare as it's seen in the final game respectively). Is it possible that Nightmare was originated here, being removed before the Final version?

[Edward850]

The current account is correct, as the game launched without any such references and later betas lacked the skill as well. A lot of the stuff in early prototypes were development cruft and didn't really mean much to the later design.

[LoatharMDPhD]

To what extent if any did the id developers play test the game on -skill 5 before releasing? did they attempt to alter the maps for more masochism or less or not at all?

[ShallowB]

Decino did a video on Nightmare where he addressed this.  He got in touch with John Romero, who confirmed it was added as a response to people who complained the game was too easy. 

 

It doesn't sound like it was play tested much, as even John Romero couldn't complete more than a few levels on Nightmare. 

 

He talks about this at about 1:00 into the video.