Poisoned projectiles

[vAethor]

I have an idea for a projectile weapon that is a poison dart that deals some damage to the target and then poisons it, also triggering a small explosion of poison gas that poisons other enemies caught in the radius.

I am guessing you call A_SpawnProjectile on the projectile's death state, making so in addition to dealing damage to the target it spawns a cloud of poison gas that deal poison-type damage to surrounding enemies before quickly dissipating. I tried to read up on poison-type damage on the Zdoom wiki but was hopelessly confused by it.

I have all the graphics and sounds made for my poison dart gun, I just need to figure out what to do next.

Another thing I want to do is cause the gun itself to release a puff of the same gas as another projectile in the fire state, in addition to the main one, causing small area-of-effect damage up close even not with a direct hit.