richard

OK, thanks. I'm now looking into how to send packets from the client to the server! Solution: I ended up implementing InvokeWandMessage which encoded the RayTraceResult generated by PythonWandItem and sent it to the server for actioning. Works!!

I've got a "wand" item that, on right-click, I wish to be able to inflict various things on mobs: set on fire or apply a potion effect to them. My two attempts at doing this are below. Apply a poison potion effect: @Nonnull @Override public ActionResult<ItemStack> onItemRightClick(@Nonnull ItemStack itemstack, World world, EntityPlayer player, EnumHand hand) { RayTraceResult target = Minecraft.getMinecraft().objectMouseOver; if (target.typeOfHit == RayTraceResult.Type.ENTITY) { if (target.entityHit instanceof EntityLivingBase) { EntityLivingBase entitylivingbase = (EntityLivingBase) target.entityHit; Potion potion = Potion.REGISTRY.getObject(new ResourceLocation("poison")); PotionEffect potioneffect = new PotionEffect(potion, 50, 1); if (potion.isInstant()) { potion.affectEntity(null, null, entitylivingbase, potioneffect.getAmplifier(), 0.5D); } else { entitylivingbase.addPotionEffect(potioneffect); } } } return ActionResult.newResult(EnumActionResult.SUCCESS, itemstack); } The result of the above is that the potion effect doesn't appear to be applied at all. Changing the code to instead set the entity on fire: @Nonnull @Override public ActionResult<ItemStack> onItemRightClick(@Nonnull ItemStack itemstack, World world, EntityPlayer player, EnumHand hand) { RayTraceResult target = Minecraft.getMinecraft().objectMouseOver; if (target.typeOfHit == RayTraceResult.Type.ENTITY) { target.entityHit.setFire(4); } return ActionResult.newResult(EnumActionResult.SUCCESS, itemstack); } This results in a brief flash of fire effect on the entity, but it does not remain on fire for the full 4 seconds that I specify. I know that I've invoked the setFire method correctly because if I do so in a hitEntity() override like so: public boolean hitEntity(ItemStack stack, EntityLivingBase target, EntityLivingBase attacker) { target.setFire(4); return true; } The entity stays on fire!