Need help with types

As already said, when you destroy a bot, before you perform the delete command on the npc, then delete all the associated effects:

delete_effect_that_belong_to_this_npc_ID(NPC_ID)
delete NPC
.
.
function delete_effect_that_belong_to_this_npc_ID(NPC_ID)
for effect.t_effect = each t_effect
if effect\NPC_ID = NPC_ID then
delete effect
endif
next
end function

Did it help ?

Sergio.