(Valid as of ZDaemon 1.10.19)

In the original Doom, effects of voodoo dolls (additional Player start #1-4 things) were tied to their respective players (1-4). In client-server source ports with players coming and going while a map is being played, keeping this 1:1 mapping is not possible. The perfect solution does not exist, but ZDaemon tries to keep most WADs playable by using the following rules when it comes to voodoo doll behaviour.

1. when a player ends up in a situation in which he would telefrag a voodoo doll, the player gets dealt telefrag damage and dies; other players and the doll remain unharmed
2. when a player damages a voodoo doll, the damage gets mirrored; i.e. he gets hurt, the voodoo doll gets hurt, but no other player gets hurt
3. when the voodoo doll gets damaged by monsters or the environment, all players take damage

1. all players in game at the time of the pickup are given the item the voodoo doll picks up; it does not matter which voodoo doll picked the item up
2. players who join the map later get all of the items the voodoo dolls picked up since the start of the map up until that point with the exception of:
   • any subclass of Health
   • subclasses of Artifact unless one of: Berserk, RadSuit, InfraRed, ArtiTorch, ArtiEgg, or ArtiFly
   • BlueArmor, EnchantedShield
3. voodoo dolls do not pick up respawned items*

*This may not be the intended behavior, and a change is being considered.

ZDaemon exhibits one peculiarity when it comes to scrollers which is relevant here since voodoo dolls are often used in combination with scrollers. The peculiarity has to do with scrollers moving extremely slow under certain conditions and its description can be found in this Doomworld post.