ZDoom

I mean like that doom 3 cyberdemon how only a certain thing can hurt it. And the other way around A_GotoIfMissileIs(missileid, state)
A_GotoIfMissileIsNot("SoulcubeMissile", See) or A_GotoIfMissileIs("BFGShot", See)
get the picture?

Getting the picture but that's something that can't be done in DECORATE. For that you'd need something much more complex that simply doesn't exist.

Make the monster +INVULNERABLE and the weapon that kills it +FOILINVUL.

You mean the projectile, don't you?

Yes, the projectile/puff actor.

is acs capible of relaying who damaged an entity, or is this impossible to integrate as well?

With the current tid system it is impossible. You'd have to rewrite significant portions of it - including a means to get detailed actor information from a tid.

Graf Zahl wrote: including a means to get detailed actor information from a tid.

I figured nothing like that was integrated into the flow of damage passing. However, since this requires a rewrite of the current system, its too much work for a questionable amount of gain.

That's the problem at the moment.

All good things come with time however. I know Zdoom is a 1 man (well, somewhat 2. Graf does a lot to) so it takes awhile to get anything done, and things requiring a lot of work rarely are done. So I just good job with what's implemented so far and it'd be great to get any of these good sounding features put in, if it's not too much work.