So I ran Brutal Doom v20 with Chex Quest...

You get the BD weapons, and the flemoids will explode into splashes of green goop. It's great.

I'm not here for a review though. Why does this happen? 

Wait, wait, wait, is there some kind of built-in compatibility going on here? Or does BD just happen to work really well with Chex Quest?

2 minutes ago, GoatLord said:

Wait, wait, wait, is there some kind of built-in compatibility going on here? Or does BD just happen to work really well with Chex Quest?

As far as I can tell, it's just a weird thing that was never made to work. It just does.

Iirc it was halfway implemented at a time when things we'll never see like Brutal Heretic also seemed to be on the table. I think mark was planning on branching out and settled on Doom 64 over Chex and Heretic/Hexen. Possible that this was just testing stuff.

1 hour ago, Cobalt0305 said:

You get the BD weapons, and the flemoids will explode into splashes of green goop. It's great.

 

I'm not here for a review though. Why does this happen? 

You'd really be better off posting this on Brutal Doom's ModDB page.

Brutal Doom does have minor compatibility with Chex Quest. In fact, you'll find Chex Quest related files inside Brutal Doom's PK3 file. Just a small joke, if you ask me. 

Of course, I can't seem to tell whether the posters above me are being sarcastic.

1 hour ago, Voros said:

Of course, I can't seem to tell whether the posters above me are being sarcastic.

They aren't. A few years ago, people were requesting BD for various Doom clones pretty regularly. Seems Mark made a little progress on it at some point and left what he'd done in. Just speculation based on memory but it's the most plausible explanation.

It's just a neat little Easter egg that Mark threw in.