ZDoom

override int SpecialMissileHit (Actor victim)
    {
        if (victim != target && victim.bSHOOTABLE && !victim.bDontRip)
        {
            HasRipped = TRUE;
        }
        return super.SpecialMissileHit(victim);
    } 

THe way I did it the actual behavior changes don't happen in SpecialMissileHit itself and it calls super.SpecialMissileHit anyway so I ended up not having to redo much of anything.
[code=php]override int SpecialMissileHit (Actor victim)
    {
        if (victim != target && victim.bSHOOTABLE && !victim.bDontRip)
        {
            HasRipped = TRUE;
        }
        return super.SpecialMissileHit(victim);
    } [/code]

[quote="Xaser"]There's also the SpecialMissileHit virtual, which would let you do the same thing and might be a slightly better place for it. Presumably there's some practical difference between the two, but I'm really not sure what it is, even after looking at the source. :shrug:[/quote]
SpecialMissileHit occurs after a good chunk of checks have already been made, such as ProjectilePassHeight, +THRUGHOST, and +MTHRUSPECIES handling. If you use CanCollideWith instead, then you may need to reimplement these checks depending on what you shove into it.

SpecialMissileHit did the trick! Thank you for your help.

Unless you're using the fancy-pants RipperLevel properties anywhere, overriding [url=https://zdoom.org/wiki/ZScript_virtual_functions#Actor]CanCollideWith[/url] in the projectile and checking if the other actor is bShootable and not bDontRip ought to suffice (don't forget to return true, too). Even though canonically that function is for testing if two objects are allowed to collide with each other, it's currently the best place to do special stuff when actors come in contact.

(If on the off chance your projectile has +NOBOSSRIP, you'll want to check to make sure the target doesn't have the bBoss flag set as well. I [i]think[/i] that's all the edge cases, though chime in if something's missing).

[EDIT] There's also the SpecialMissileHit virtual, which would let you do the same thing and might be a slightly better place for it. Presumably there's some practical difference between the two, but I'm really not sure what it is, even after looking at the source. :shrug:

Thread title. What would be the best way to determine if a ripper projectile is actively ripping through an actor? I am trying to make an actor that changes behavior after ripping through a actor.