SViking

It doesn't appear to have any sub events. The Forge hook is onAnvilChange(...) which is called from within ContainerRepair.updateRepairOutput(). Each event does appear to be a separate call from this same point. That's as much as I've determined so far.

Thanks for the reply. Of course, some of the repeating in my test due to execution on both client and server. However, my laziness was fortuitous, as I sometimes saw a different number of events on one side vs the other. That would further support your notion of the event firing on multiple ticks, with lag as a contributor. I'm digging a little more into the Forge hook that allows the anvil events to see if there's a possible resolution. At least I know now I'm not chasing my own tail. Haha...same here!

When subscribing to the AnvilUpdateEvent, I seem to be getting multiple events for a single action of filling the left and right slots on the anvil. This is for Forge 1.9-12.16.0.1811-1.9. Am I doing something wrong here, is this a bug or other? Here's my test code and output from one test run: Main class: package com.sviking.practicalanvil; import com.sviking.practicalanvil.event.PAEventHandler; import net.minecraftforge.common.MinecraftForge; import net.minecraftforge.fml.common.FMLCommonHandler; import net.minecraftforge.fml.common.Mod; import net.minecraftforge.fml.common.Mod.EventHandler; import net.minecraftforge.fml.common.Mod.Instance; import net.minecraftforge.fml.common.event.FMLInitializationEvent; import net.minecraftforge.fml.common.event.FMLPostInitializationEvent; import net.minecraftforge.fml.common.event.FMLPreInitializationEvent; @Mod(modid = Main.MODID, name = Main.MODNAME, version = Main.VERSION) public class Main { public static final String MODID = "practicalanvil"; public static final String MODNAME = "Practical Anvil Mod"; public static final String VERSION = "1.0.0"; @Instance public static Main instance = new Main(); @EventHandler public void preInit(FMLPreInitializationEvent e) { } @EventHandler public void init(FMLInitializationEvent e) { MinecraftForge.EVENT_BUS.register(new PAEventHandler()); } @EventHandler public void postInit(FMLPostInitializationEvent e) { } } Event handler: package com.sviking.practicalanvil.event; import net.minecraftforge.event.AnvilUpdateEvent; import net.minecraftforge.event.entity.player.AnvilRepairEvent; import net.minecraftforge.fml.common.eventhandler.EventPriority; import net.minecraftforge.fml.common.eventhandler.SubscribeEvent; public class PAEventHandler { @SubscribeEvent public void onAnvilUpdate(AnvilUpdateEvent e) { System.out.println(e); e.setCanceled(true); } } Sample output (single action of filling left and right slots): [21:42:28] [Client thread/INFO] [sTDOUT]: [com.sviking.practicalanvil.event.PAEventHandler:onAnvilUpdate:11]: net.minecraftforge.event.AnvilUpdateEvent@384bd992 [21:42:28] [Client thread/INFO] [sTDOUT]: [com.sviking.practicalanvil.event.PAEventHandler:onAnvilUpdate:11]: net.minecraftforge.event.AnvilUpdateEvent@10fae499 [21:42:28] [Client thread/INFO] [sTDOUT]: [com.sviking.practicalanvil.event.PAEventHandler:onAnvilUpdate:11]: net.minecraftforge.event.AnvilUpdateEvent@259a9966 [21:42:28] [server thread/INFO] [sTDOUT]: [com.sviking.practicalanvil.event.PAEventHandler:onAnvilUpdate:11]: net.minecraftforge.event.AnvilUpdateEvent@b0f027e [21:42:28] [server thread/INFO] [sTDOUT]: [com.sviking.practicalanvil.event.PAEventHandler:onAnvilUpdate:11]: net.minecraftforge.event.AnvilUpdateEvent@3505b6d9 [21:42:28] [server thread/INFO] [sTDOUT]: [com.sviking.practicalanvil.event.PAEventHandler:onAnvilUpdate:11]: net.minecraftforge.event.AnvilUpdateEvent@6eef4800 [21:42:28] [Client thread/INFO] [sTDOUT]: [com.sviking.practicalanvil.event.PAEventHandler:onAnvilUpdate:11]: net.minecraftforge.event.AnvilUpdateEvent@7b7ef483 [21:42:28] [Client thread/INFO] [sTDOUT]: [com.sviking.practicalanvil.event.PAEventHandler:onAnvilUpdate:11]: net.minecraftforge.event.AnvilUpdateEvent@1d9f2537 I'll also note that the number of events generated varies from as few as 4 to as many as 10. I've experienced similar behavior with AnvilRepairEvent, though not as extreme. Thanks in advance.