ZDoom

It doesn't seem possible with the current map cluster definition system to have a different piece of text (or no text at all) if the player exits a map at the end of a cluster via a secret exit versus a normal exit. This doesn't come up with the stock Doom 1 & 2 setups because their secret levels always come in the middle of their cluster rather than on the last map, but this would be useful functionality - say, for implementing a "good" or "bad" ending in separate maps - and is not (AFAICT, looking over the wiki and code) currently possible.

Doesn't it work if you give the secret map's cluster an enter text?

Graf Zahl wrote:Doesn't it work if you give the secret map's cluster an enter text?

Ah, it does, so I should've been more specific in my request: I want there to be no story text if the player secret-exits from map 20, but some story text if they normal-exit from map 20. Setting the secret level's cluster's entertext to "" doesn't work, it just shows the previous cluster's exittext.

Simple solution: Use the same cluster for the secret map as for map 20.

Graf Zahl wrote:Simple solution: Use the same cluster for the secret map as for map 20.

Ah, that only works if there's a non-secret map after 20, which there is not in this case.
To spell it out, here's what should happen when the player:
- exits map20 normally: show story text, then go to curtain call (cast)
- exits map20 through secret: go to map21
- exits map21: show story text, then go to curtain call

For future searchers who happen to want to do this same specific thing, I was able to work around this by creating a custom intermission that just displays the text, the continues to the next map as intended.

Added as a per-map feature, because making exit texts part of the cluster was a really bad idea.
There's now a complete set of properties to define intermission texts for specific transitions from any map to a specific other one.