Monsers can't sleep in beds

src/main/java/com/minelittlepony/unicopia/player/Hooks.java

@@ -11,6 +11,7 @@ import net.minecraftforge.event.entity.item.ItemTossEvent;
 import net.minecraftforge.event.entity.living.LivingEntityUseItemEvent;
 import net.minecraftforge.event.entity.player.PlayerDropsEvent;
 import net.minecraftforge.event.entity.player.PlayerFlyableFallEvent;
+import net.minecraftforge.event.entity.player.PlayerSleepInBedEvent;
 import net.minecraftforge.fml.common.Mod.EventBusSubscriber;
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
 import net.minecraftforge.fml.common.gameevent.TickEvent;
@@ -44,6 +45,13 @@ class Hooks {
             .forEach(item -> item.setPlayerSpecies(race));
     }
 
+    @SubscribeEvent
+    public static void onPlayerTrySleep(PlayerSleepInBedEvent event) {
+        if (event.getResultStatus() == null) {
+            event.setResult(PlayerSpeciesList.instance().getPlayer(event.getEntityPlayer()).trySleep(event.getPos()));
+        }
+    }
+
     @SubscribeEvent
     public static void onPlayerFall(PlayerFlyableFallEvent event) {
         PlayerSpeciesList.instance().getPlayer(event.getEntityPlayer()).onFall(event.getDistance(), event.getMultiplier());

src/main/java/com/minelittlepony/unicopia/player/IPlayer.java

@@ -13,9 +13,11 @@ import com.mojang.authlib.GameProfile;
 
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.player.EntityPlayer;
+import net.minecraft.entity.player.EntityPlayer.SleepResult;
 import net.minecraft.item.ItemFood;
 import net.minecraft.item.ItemStack;
 import net.minecraft.server.MinecraftServer;
+import net.minecraft.util.math.BlockPos;
 import net.minecraftforge.fml.common.FMLCommonHandler;
 
 /**
@@ -127,6 +129,15 @@ public interface IPlayer extends ICaster<EntityPlayer>, IRaceContainer<EntityPla
      */
     boolean onProjectileImpact(Entity projectile);
 
+    /**
+     * Attempts to sleep in a bed.
+     *
+     * @param pos The position of the bed
+     *
+     * @return The sleep result.
+     */
+    SleepResult trySleep(BlockPos pos);
+
     /**
      * Returns true if this player is the use.
      */

src/main/java/com/minelittlepony/unicopia/player/PlayerCapabilities.java

@@ -11,6 +11,7 @@ import com.minelittlepony.unicopia.Race;
 import com.minelittlepony.unicopia.Unicopia;
 import com.minelittlepony.unicopia.enchanting.PageState;
 import com.minelittlepony.unicopia.init.UEffects;
+import com.minelittlepony.unicopia.init.UItems;
 import com.minelittlepony.unicopia.network.EffectSync;
 import com.minelittlepony.unicopia.network.MsgPlayerCapabilities;
 import com.minelittlepony.unicopia.spell.IMagicEffect;
@@ -21,6 +22,7 @@ import com.minelittlepony.unicopia.spell.SpellRegistry;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.entity.player.EntityPlayerMP;
+import net.minecraft.entity.player.EntityPlayer.SleepResult;
 import net.minecraft.init.MobEffects;
 import net.minecraft.item.ItemFood;
 import net.minecraft.item.ItemStack;
@@ -32,6 +34,8 @@ import net.minecraft.network.play.server.SPacketSetPassengers;
 import net.minecraft.potion.PotionEffect;
 import net.minecraft.stats.StatList;
 import net.minecraft.util.ResourceLocation;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.text.TextComponentTranslation;
 import net.minecraft.world.EnumDifficulty;
 
 class PlayerCapabilities implements IPlayer {
@@ -268,6 +272,24 @@ class PlayerCapabilities implements IPlayer {
         return false;
     }
 
+    @Override
+    public SleepResult trySleep(BlockPos pos) {
+
+
+        if (getInventory().isWearing(UItems.alicorn_amulet)) {
+            if (!getWorld().isRemote) {
+                entity.sendStatusMessage(new TextComponentTranslation("tile.bed.youAreAMonster"), true);
+            }
+            return SleepResult.OTHER_PROBLEM;
+        }
+
+        if (findAllSpellsInRange(10).anyMatch(c -> c instanceof IPlayer && ((IPlayer)c).getInventory().isWearing(UItems.alicorn_amulet))) {
+            return SleepResult.NOT_SAFE;
+        }
+
+        return null;
+    }
+
     @Override
     public IFood getFood() {
         return food;

src/main/resources/assets/unicopia/lang/en_US.lang

@@ -32,6 +32,8 @@ item.staff_meadow_brook.tagline=It's a big stick
 item.alicorn_amulet.name=The Alicorn Amulet
 item.alicorn_amulet.tagline=Time Worn: %s
 
+tile.bed.youAreAMonster=You may not rest here, you are the monster
+
 item.gem.name=Gem
 item.gem.enchanted.name=Gem of %s
 item.corrupted_gem.name=Fractured Gem