diff --git a/api/src/main/java/net/momirealms/customfishing/api/mechanic/config/ConfigManager.java b/api/src/main/java/net/momirealms/customfishing/api/mechanic/config/ConfigManager.java
index 3a38cb22..d97f3be6 100644
--- a/api/src/main/java/net/momirealms/customfishing/api/mechanic/config/ConfigManager.java
+++ b/api/src/main/java/net/momirealms/customfishing/api/mechanic/config/ConfigManager.java
@@ -37,6 +37,7 @@ import net.momirealms.customfishing.api.mechanic.entity.EntityConfig;
 import net.momirealms.customfishing.api.mechanic.event.EventCarrier;
 import net.momirealms.customfishing.api.mechanic.hook.HookConfig;
 import net.momirealms.customfishing.api.mechanic.loot.Loot;
+import net.momirealms.customfishing.api.mechanic.loot.operation.WeightOperation;
 import net.momirealms.customfishing.api.mechanic.requirement.Requirement;
 import net.momirealms.customfishing.api.mechanic.totem.TotemConfig;
 import net.momirealms.customfishing.common.config.ConfigLoader;
@@ -59,7 +60,6 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.function.BiConsumer;
-import java.util.function.BiFunction;
 import java.util.function.Consumer;
 import java.util.function.Function;
 
@@ -471,9 +471,9 @@ public abstract class ConfigManager implements ConfigLoader, Reloadable {
         return lootFormatFunctions;
     }
 
-    public abstract List<Pair<String, BiFunction<Context<Player>, Double, Double>>> parseWeightOperation(List<String> ops);
+    public abstract List<Pair<String, WeightOperation>> parseWeightOperation(List<String> ops, Function<String, Boolean> validator);
 
-    public abstract List<Pair<String, BiFunction<Context<Player>, Double, Double>>> parseGroupWeightOperation(List<String> gops);
+    public abstract List<Pair<String, WeightOperation>> parseGroupWeightOperation(List<String> gops);
 
     @Deprecated
     public Map<String, Node<ConfigParserFunction>> getDefaultFormatFunctions() {
diff --git a/api/src/main/java/net/momirealms/customfishing/api/mechanic/context/ContextKeys.java b/api/src/main/java/net/momirealms/customfishing/api/mechanic/context/ContextKeys.java
index c1eb33f4..67ab8ec0 100644
--- a/api/src/main/java/net/momirealms/customfishing/api/mechanic/context/ContextKeys.java
+++ b/api/src/main/java/net/momirealms/customfishing/api/mechanic/context/ContextKeys.java
@@ -76,6 +76,7 @@ public class ContextKeys<T> {
     public static final ContextKeys<Integer> AMOUNT = of("amount", Integer.class);
     public static final ContextKeys<Integer> TOTAL_AMOUNT = of("total_amount", Integer.class);
     public static final ContextKeys<Double> WEIGHT = of("0", Double.class);
+    public static final ContextKeys<Double> TOTAL_WEIGHT = of("1", Double.class);
     public static final ContextKeys<String> TIME_LEFT = of("time_left", String.class);
     public static final ContextKeys<String> PROGRESS = of("progress", String.class);
     public static final ContextKeys<Float> RECORD = of("record", Float.class);
diff --git a/api/src/main/java/net/momirealms/customfishing/api/mechanic/effect/Effect.java b/api/src/main/java/net/momirealms/customfishing/api/mechanic/effect/Effect.java
index cb38d7a6..23757ec6 100644
--- a/api/src/main/java/net/momirealms/customfishing/api/mechanic/effect/Effect.java
+++ b/api/src/main/java/net/momirealms/customfishing/api/mechanic/effect/Effect.java
@@ -17,13 +17,11 @@
 
 package net.momirealms.customfishing.api.mechanic.effect;
 
-import net.momirealms.customfishing.api.mechanic.context.Context;
+import net.momirealms.customfishing.api.mechanic.loot.operation.WeightOperation;
 import net.momirealms.customfishing.common.util.Pair;
-import org.bukkit.entity.Player;
 
 import java.util.List;
 import java.util.Map;
-import java.util.function.BiFunction;
 
 /**
  * Represents an effect applied in the fishing.
@@ -234,7 +232,7 @@ public interface Effect {
      *
      * @return the list of weight operations
      */
-    List<Pair<String, BiFunction<Context<Player>, Double, Double>>> weightOperations();
+    List<Pair<String, WeightOperation>> weightOperations();
 
     /**
      * Adds the list of weight operations.
@@ -242,14 +240,14 @@ public interface Effect {
      * @param weightOperations the list of weight operations to add
      * @return the effect instance
      */
-    Effect weightOperations(List<Pair<String, BiFunction<Context<Player>, Double, Double>>> weightOperations);
+    Effect weightOperations(List<Pair<String, WeightOperation>> weightOperations);
 
     /**
      * Gets the list of weight operations that are conditions ignored.
      *
      * @return the list of weight operations that are conditions ignored
      */
-    List<Pair<String, BiFunction<Context<Player>, Double, Double>>> weightOperationsIgnored();
+    List<Pair<String, WeightOperation>> weightOperationsIgnored();
 
     /**
      * Adds the list of weight operations that are conditions ignored.
@@ -257,7 +255,7 @@ public interface Effect {
      * @param weightOperations the list of weight operations that are conditions ignored
      * @return the effect instance
      */
-    Effect weightOperationsIgnored(List<Pair<String, BiFunction<Context<Player>, Double, Double>>> weightOperations);
+    Effect weightOperationsIgnored(List<Pair<String, WeightOperation>> weightOperations);
 
     /**
      * Combines this effect with another effect.
diff --git a/api/src/main/java/net/momirealms/customfishing/api/mechanic/effect/EffectImpl.java b/api/src/main/java/net/momirealms/customfishing/api/mechanic/effect/EffectImpl.java
index 4cc1a562..3f693d8b 100644
--- a/api/src/main/java/net/momirealms/customfishing/api/mechanic/effect/EffectImpl.java
+++ b/api/src/main/java/net/momirealms/customfishing/api/mechanic/effect/EffectImpl.java
@@ -1,14 +1,12 @@
 package net.momirealms.customfishing.api.mechanic.effect;
 
-import net.momirealms.customfishing.api.mechanic.context.Context;
+import net.momirealms.customfishing.api.mechanic.loot.operation.WeightOperation;
 import net.momirealms.customfishing.common.util.Pair;
-import org.bukkit.entity.Player;
 
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.function.BiFunction;
 
 public class EffectImpl implements Effect {
 
@@ -24,8 +22,8 @@ public class EffectImpl implements Effect {
     private double waitTimeMultiplier = 1;
     private double difficultyAdder = 0;
     private double difficultyMultiplier = 1;
-    private final List<Pair<String, BiFunction<Context<Player>, Double, Double>>> weightOperations = new ArrayList<>();
-    private final List<Pair<String, BiFunction<Context<Player>, Double, Double>>> weightOperationsIgnored = new ArrayList<>();
+    private final List<Pair<String, WeightOperation>> weightOperations = new ArrayList<>();
+    private final List<Pair<String, WeightOperation>> weightOperationsIgnored = new ArrayList<>();
 
     @Override
     public Map<EffectProperties<?>, Object> properties() {
@@ -172,23 +170,23 @@ public class EffectImpl implements Effect {
     }
 
     @Override
-    public List<Pair<String, BiFunction<Context<Player>, Double, Double>>> weightOperations() {
+    public List<Pair<String, WeightOperation>> weightOperations() {
         return weightOperations;
     }
 
     @Override
-    public Effect weightOperations(List<Pair<String, BiFunction<Context<Player>, Double, Double>>> weightOperations) {
+    public Effect weightOperations(List<Pair<String, WeightOperation>> weightOperations) {
         this.weightOperations.addAll(weightOperations);
         return this;
     }
 
     @Override
-    public List<Pair<String, BiFunction<Context<Player>, Double, Double>>> weightOperationsIgnored() {
+    public List<Pair<String, WeightOperation>> weightOperationsIgnored() {
         return weightOperationsIgnored;
     }
 
     @Override
-    public Effect weightOperationsIgnored(List<Pair<String, BiFunction<Context<Player>, Double, Double>>> weightOperations) {
+    public Effect weightOperationsIgnored(List<Pair<String, WeightOperation>> weightOperations) {
         this.weightOperationsIgnored.addAll(weightOperations);
         return this;
     }
diff --git a/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/AddWeightOperation.java b/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/AddWeightOperation.java
new file mode 100644
index 00000000..22c73708
--- /dev/null
+++ b/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/AddWeightOperation.java
@@ -0,0 +1,38 @@
+/*
+ *  Copyright (C) <2024> <XiaoMoMi>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package net.momirealms.customfishing.api.mechanic.loot.operation;
+
+import net.momirealms.customfishing.api.mechanic.context.Context;
+import net.momirealms.customfishing.api.mechanic.misc.value.MathValue;
+import org.bukkit.entity.Player;
+
+import java.util.Map;
+
+public class AddWeightOperation implements WeightOperation {
+
+    private final MathValue<Player> arg;
+
+    public AddWeightOperation(MathValue<Player> arg) {
+        this.arg = arg;
+    }
+
+    @Override
+    public Double apply(Context<Player> context, Double weight, Map<String, Double> weights) {
+        return weight + arg.evaluate(context);
+    }
+}
diff --git a/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/CustomWeightOperation.java b/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/CustomWeightOperation.java
new file mode 100644
index 00000000..a26bf137
--- /dev/null
+++ b/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/CustomWeightOperation.java
@@ -0,0 +1,64 @@
+/*
+ *  Copyright (C) <2024> <XiaoMoMi>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package net.momirealms.customfishing.api.mechanic.loot.operation;
+
+import net.momirealms.customfishing.api.mechanic.context.Context;
+import net.momirealms.customfishing.api.mechanic.context.ContextKeys;
+import net.momirealms.customfishing.api.mechanic.misc.value.MathValue;
+import org.bukkit.entity.Player;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+
+public class CustomWeightOperation implements WeightOperation {
+
+    private final MathValue<Player> arg;
+    private final boolean hasTotalWeight;
+    private final List<String> otherWeights;
+
+    public CustomWeightOperation(MathValue<Player> arg, boolean hasTotalWeight, List<String> otherWeights) {
+        this.arg = arg;
+        this.hasTotalWeight = hasTotalWeight;
+        this.otherWeights = otherWeights;
+    }
+
+    @Override
+    public Double apply(Context<Player> context, Double weight, Map<String, Double> weights) {
+        context.arg(ContextKeys.WEIGHT, weight);
+        if (hasTotalWeight) {
+            context.arg(ContextKeys.TOTAL_WEIGHT, getValidTotalWeight(weights.values()));
+        }
+        if (!otherWeights.isEmpty()) {
+            for (String otherWeight : otherWeights) {
+                context.arg(ContextKeys.of("loot_" + otherWeight, Double.class), weights.get(otherWeight));
+            }
+        }
+        return arg.evaluate(context);
+    }
+
+    private double getValidTotalWeight(Collection<Double> weights) {
+        double totalWeight = 0;
+        for (Double weight : weights) {
+            if (weight > 0) {
+                totalWeight += weight;
+            }
+        }
+        return totalWeight;
+    }
+}
diff --git a/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/DivideWeightOperation.java b/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/DivideWeightOperation.java
new file mode 100644
index 00000000..ca2200d2
--- /dev/null
+++ b/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/DivideWeightOperation.java
@@ -0,0 +1,38 @@
+/*
+ *  Copyright (C) <2024> <XiaoMoMi>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package net.momirealms.customfishing.api.mechanic.loot.operation;
+
+import net.momirealms.customfishing.api.mechanic.context.Context;
+import net.momirealms.customfishing.api.mechanic.misc.value.MathValue;
+import org.bukkit.entity.Player;
+
+import java.util.Map;
+
+public class DivideWeightOperation implements WeightOperation {
+
+    private final MathValue<Player> arg;
+
+    public DivideWeightOperation(MathValue<Player> arg) {
+        this.arg = arg;
+    }
+
+    @Override
+    public Double apply(Context<Player> context, Double weight, Map<String, Double> weights) {
+        return weight / arg.evaluate(context);
+    }
+}
diff --git a/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/ModuloWeightOperation.java b/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/ModuloWeightOperation.java
new file mode 100644
index 00000000..529d7a55
--- /dev/null
+++ b/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/ModuloWeightOperation.java
@@ -0,0 +1,38 @@
+/*
+ *  Copyright (C) <2024> <XiaoMoMi>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package net.momirealms.customfishing.api.mechanic.loot.operation;
+
+import net.momirealms.customfishing.api.mechanic.context.Context;
+import net.momirealms.customfishing.api.mechanic.misc.value.MathValue;
+import org.bukkit.entity.Player;
+
+import java.util.Map;
+
+public class ModuloWeightOperation implements WeightOperation {
+
+    private final MathValue<Player> arg;
+
+    public ModuloWeightOperation(MathValue<Player> arg) {
+        this.arg = arg;
+    }
+
+    @Override
+    public Double apply(Context<Player> context, Double weight, Map<String, Double> weights) {
+        return weight % arg.evaluate(context);
+    }
+}
diff --git a/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/MultiplyWeightOperation.java b/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/MultiplyWeightOperation.java
new file mode 100644
index 00000000..757b99dd
--- /dev/null
+++ b/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/MultiplyWeightOperation.java
@@ -0,0 +1,38 @@
+/*
+ *  Copyright (C) <2024> <XiaoMoMi>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package net.momirealms.customfishing.api.mechanic.loot.operation;
+
+import net.momirealms.customfishing.api.mechanic.context.Context;
+import net.momirealms.customfishing.api.mechanic.misc.value.MathValue;
+import org.bukkit.entity.Player;
+
+import java.util.Map;
+
+public class MultiplyWeightOperation implements WeightOperation {
+
+    private final MathValue<Player> arg;
+
+    public MultiplyWeightOperation(MathValue<Player> arg) {
+        this.arg = arg;
+    }
+
+    @Override
+    public Double apply(Context<Player> context, Double weight, Map<String, Double> weights) {
+        return weight * arg.evaluate(context);
+    }
+}
diff --git a/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/ReduceWeightOperation.java b/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/ReduceWeightOperation.java
new file mode 100644
index 00000000..ba440e6c
--- /dev/null
+++ b/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/ReduceWeightOperation.java
@@ -0,0 +1,38 @@
+/*
+ *  Copyright (C) <2024> <XiaoMoMi>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package net.momirealms.customfishing.api.mechanic.loot.operation;
+
+import net.momirealms.customfishing.api.mechanic.context.Context;
+import net.momirealms.customfishing.api.mechanic.misc.value.MathValue;
+import org.bukkit.entity.Player;
+
+import java.util.Map;
+
+public class ReduceWeightOperation implements WeightOperation {
+
+    private final MathValue<Player> arg;
+
+    public ReduceWeightOperation(MathValue<Player> arg) {
+        this.arg = arg;
+    }
+
+    @Override
+    public Double apply(Context<Player> context, Double weight, Map<String, Double> weights) {
+        return weight - arg.evaluate(context);
+    }
+}
diff --git a/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/WeightOperation.java b/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/WeightOperation.java
new file mode 100644
index 00000000..3e9fcd7d
--- /dev/null
+++ b/api/src/main/java/net/momirealms/customfishing/api/mechanic/loot/operation/WeightOperation.java
@@ -0,0 +1,28 @@
+/*
+ *  Copyright (C) <2024> <XiaoMoMi>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package net.momirealms.customfishing.api.mechanic.loot.operation;
+
+import net.momirealms.customfishing.api.mechanic.context.Context;
+import net.momirealms.customfishing.common.util.TriFunction;
+import org.bukkit.entity.Player;
+
+import java.util.Map;
+
+@FunctionalInterface
+public interface WeightOperation extends TriFunction<Context<Player>, Double, Map<String, Double>, Double> {
+}
diff --git a/core/src/main/java/net/momirealms/customfishing/bukkit/BukkitCustomFishingPluginImpl.java b/core/src/main/java/net/momirealms/customfishing/bukkit/BukkitCustomFishingPluginImpl.java
index 61c56111..12cf2f1f 100644
--- a/core/src/main/java/net/momirealms/customfishing/bukkit/BukkitCustomFishingPluginImpl.java
+++ b/core/src/main/java/net/momirealms/customfishing/bukkit/BukkitCustomFishingPluginImpl.java
@@ -184,7 +184,7 @@ public class BukkitCustomFishingPluginImpl extends BukkitCustomFishingPlugin {
 
         this.actionManager.reload();
         this.requirementManager.reload();
-        this.gameManager.reload();
+        this.gameManager.unload();
 
         // before ConfigManager
         this.placeholderManager.reload();
@@ -205,6 +205,7 @@ public class BukkitCustomFishingPluginImpl extends BukkitCustomFishingPlugin {
         this.eventManager.load();
         this.entityManager.load();
         this.lootManager.load();
+        this.gameManager.load();
         this.blockManager.load();
         this.effectManager.load();
         this.hookManager.load();
diff --git a/core/src/main/java/net/momirealms/customfishing/bukkit/config/BukkitConfigManager.java b/core/src/main/java/net/momirealms/customfishing/bukkit/config/BukkitConfigManager.java
index a2da1684..737a6fc7 100644
--- a/core/src/main/java/net/momirealms/customfishing/bukkit/config/BukkitConfigManager.java
+++ b/core/src/main/java/net/momirealms/customfishing/bukkit/config/BukkitConfigManager.java
@@ -48,6 +48,8 @@ import net.momirealms.customfishing.api.mechanic.effect.EffectProperties;
 import net.momirealms.customfishing.api.mechanic.event.EventManager;
 import net.momirealms.customfishing.api.mechanic.item.ItemEditor;
 import net.momirealms.customfishing.api.mechanic.loot.Loot;
+import net.momirealms.customfishing.api.mechanic.loot.operation.*;
+import net.momirealms.customfishing.api.mechanic.misc.placeholder.BukkitPlaceholderManager;
 import net.momirealms.customfishing.api.mechanic.misc.value.MathValue;
 import net.momirealms.customfishing.api.mechanic.misc.value.TextValue;
 import net.momirealms.customfishing.api.mechanic.requirement.Requirement;
@@ -90,18 +92,20 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.util.*;
 import java.util.function.BiConsumer;
-import java.util.function.BiFunction;
 import java.util.function.Function;
 
 public class BukkitConfigManager extends ConfigManager {
 
     private static YamlDocument MAIN_CONFIG;
     private static Particle dustParticle;
-
     public static YamlDocument getMainConfig() {
         return MAIN_CONFIG;
     }
 
+    private Function<String, Boolean> lootValidator = (id) -> {
+        return plugin.getLootManager().getLoot(id).isPresent();
+    };
+
     public BukkitConfigManager(BukkitCustomFishingPlugin plugin) {
         super(plugin);
         this.registerBuiltInItemProperties();
@@ -627,7 +631,7 @@ public class BukkitConfigManager extends ConfigManager {
                 }));
             }
             case "weight-mod" -> {
-                var op = parseWeightOperation(section.getStringList("value"));
+                var op = parseWeightOperation(section.getStringList("value"), lootValidator);
                 return (((effect, context, phase) -> {
                     if (phase == 1) {
                         effect.weightOperations(op);
@@ -636,7 +640,7 @@ public class BukkitConfigManager extends ConfigManager {
                 }));
             }
             case "weight-mod-ignore-conditions" -> {
-                var op = parseWeightOperation(section.getStringList("value"));
+                var op = parseWeightOperation(section.getStringList("value"), lootValidator);
                 return (((effect, context, phase) -> {
                     if (phase == 1) {
                         effect.weightOperationsIgnored(op);
@@ -782,63 +786,73 @@ public class BukkitConfigManager extends ConfigManager {
         }
     }
 
-    private BiFunction<Context<Player>, Double, Double> parseWeightOperation(String op) {
+    private WeightOperation parseWeightOperation(String op) {
         switch (op.charAt(0)) {
             case '/' -> {
                 MathValue<Player> arg = MathValue.auto(op.substring(1));
-                return (context, weight) -> weight / arg.evaluate(context);
+                return new DivideWeightOperation(arg);
             }
             case '*' -> {
                 MathValue<Player> arg = MathValue.auto(op.substring(1));
-                return (context, weight) -> weight * arg.evaluate(context);
+                return new MultiplyWeightOperation(arg);
             }
             case '-' -> {
                 MathValue<Player> arg = MathValue.auto(op.substring(1));
-                return (context, weight) -> weight - arg.evaluate(context);
+                return new ReduceWeightOperation(arg);
             }
             case '%' -> {
                 MathValue<Player> arg = MathValue.auto(op.substring(1));
-                return (context, weight) -> weight % arg.evaluate(context);
+                return new ModuloWeightOperation(arg);
             }
             case '+' -> {
                 MathValue<Player> arg = MathValue.auto(op.substring(1));
-                return (context, weight) -> weight + arg.evaluate(context);
+                return new AddWeightOperation(arg);
             }
             case '=' -> {
-                MathValue<Player> arg = MathValue.auto(op.substring(1));
-                return (context, weight) -> {
-                    context.arg(ContextKeys.WEIGHT, weight);
-                    return arg.evaluate(context);
-                };
+                String expression = op.substring(1);
+                MathValue<Player> arg = MathValue.auto(expression);
+                List<String> placeholders = BukkitPlaceholderManager.getInstance().resolvePlaceholders(expression);
+                List<String> otherWeights = new ArrayList<>();
+                for (String placeholder : placeholders) {
+                    if (placeholder.startsWith("{loot_")) {
+                        otherWeights.add(placeholder.substring("{loot_".length(), placeholder.length() - 1));
+                    }
+                }
+                return new CustomWeightOperation(arg, expression.contains("{1}"), otherWeights);
             }
             default -> throw new IllegalArgumentException("Invalid weight operation: " + op);
         }
     }
 
     @Override
-    public List<Pair<String, BiFunction<Context<Player>, Double, Double>>> parseWeightOperation(List<String> ops) {
-        List<Pair<String, BiFunction<Context<Player>, Double, Double>>> result = new ArrayList<>();
+    public List<Pair<String, WeightOperation>> parseWeightOperation(List<String> ops, Function<String, Boolean> validator) {
+        List<Pair<String, WeightOperation>> result = new ArrayList<>();
         for (String op : ops) {
             String[] split = op.split(":", 2);
             if (split.length < 2) {
                 plugin.getPluginLogger().warn("Illegal weight operation: " + op);
                 continue;
             }
-            result.add(Pair.of(split[0], parseWeightOperation(split[1])));
+            String id = split[0];
+            if (!validator.apply(id)) {
+                plugin.getPluginLogger().warn("Illegal weight operation: " + op + ". Id " + id + " is not valid");
+                continue;
+            }
+            result.add(Pair.of(id, parseWeightOperation(split[1])));
         }
         return result;
     }
 
     @Override
-    public List<Pair<String, BiFunction<Context<Player>, Double, Double>>> parseGroupWeightOperation(List<String> gops) {
-        List<Pair<String, BiFunction<Context<Player>, Double, Double>>> result = new ArrayList<>();
+    public List<Pair<String, WeightOperation>> parseGroupWeightOperation(List<String> gops) {
+        List<Pair<String, WeightOperation>> result = new ArrayList<>();
         for (String gop : gops) {
             String[] split = gop.split(":", 2);
             if (split.length < 2) {
                 plugin.getPluginLogger().warn("Illegal weight operation: " + gop);
                 continue;
             }
-            BiFunction<Context<Player>, Double, Double> operation = parseWeightOperation(split[1]);
+            WeightOperation operation = parseWeightOperation(split[1]);
             for (String member : plugin.getLootManager().getGroupMembers(split[0])) {
                 result.add(Pair.of(member, operation));
             }
diff --git a/core/src/main/java/net/momirealms/customfishing/bukkit/game/BukkitGameManager.java b/core/src/main/java/net/momirealms/customfishing/bukkit/game/BukkitGameManager.java
index 87f9cb28..ea9d2e3e 100644
--- a/core/src/main/java/net/momirealms/customfishing/bukkit/game/BukkitGameManager.java
+++ b/core/src/main/java/net/momirealms/customfishing/bukkit/game/BukkitGameManager.java
@@ -27,6 +27,7 @@ import net.momirealms.customfishing.api.mechanic.context.ContextKeys;
 import net.momirealms.customfishing.api.mechanic.effect.Effect;
 import net.momirealms.customfishing.api.mechanic.fishing.CustomFishingHook;
 import net.momirealms.customfishing.api.mechanic.game.*;
+import net.momirealms.customfishing.api.mechanic.loot.operation.WeightOperation;
 import net.momirealms.customfishing.api.mechanic.misc.value.MathValue;
 import net.momirealms.customfishing.api.mechanic.misc.value.TextValue;
 import net.momirealms.customfishing.api.mechanic.requirement.ConditionalElement;
@@ -52,7 +53,7 @@ public class BukkitGameManager implements GameManager {
     private final BukkitCustomFishingPlugin plugin;
     private final Map<String, GameFactory> gameFactoryMap = new HashMap<>();
     private final Map<String, Game> gameMap = new HashMap<>();
-    private final LinkedHashMap<String, ConditionalElement<List<Pair<String, BiFunction<Context<Player>, Double, Double>>>, Player>> gameConditions = new LinkedHashMap<>();
+    private final LinkedHashMap<String, ConditionalElement<List<Pair<String, WeightOperation>>, Player>> gameConditions = new LinkedHashMap<>();
     private static final String EXPANSION_FOLDER = "expansions/minigame";
 
     public BukkitGameManager(BukkitCustomFishingPlugin plugin) {
@@ -87,23 +88,23 @@ public class BukkitGameManager implements GameManager {
         this.gameMap.clear();
     }
 
-    private ConditionalElement<List<Pair<String, BiFunction<Context<Player>, Double, Double>>>, Player> parseGameConditions(Section section) {
+    private ConditionalElement<List<Pair<String, WeightOperation>>, Player> parseGameConditions(Section section) {
         Section subSection = section.getSection("sub-groups");
         if (subSection == null) {
             return new ConditionalElement<>(
-                    plugin.getConfigManager().parseWeightOperation(section.getStringList("list")),
+                    plugin.getConfigManager().parseWeightOperation(section.getStringList("list"), (id) -> getGame(id).isPresent()),
                     Map.of(),
                     plugin.getRequirementManager().parseRequirements(section.getSection("conditions"), false)
             );
         } else {
-            HashMap<String, ConditionalElement<List<Pair<String, BiFunction<Context<Player>, Double, Double>>>, Player>> subElements = new HashMap<>();
+            HashMap<String, ConditionalElement<List<Pair<String, WeightOperation>>, Player>> subElements = new HashMap<>();
             for (Map.Entry<String, Object> entry : subSection.getStringRouteMappedValues(false).entrySet()) {
                 if (entry.getValue() instanceof Section innerSection) {
                     subElements.put(entry.getKey(), parseGameConditions(innerSection));
                 }
             }
             return new ConditionalElement<>(
-                    plugin.getConfigManager().parseWeightOperation(section.getStringList("list")),
+                    plugin.getConfigManager().parseWeightOperation(section.getStringList("list"), (id) -> getGame(id).isPresent()),
                     subElements,
                     plugin.getRequirementManager().parseRequirements(section.getSection("conditions"), false)
             );
@@ -143,24 +144,24 @@ public class BukkitGameManager implements GameManager {
     @Nullable
     @Override
     public Game getNextGame(Effect effect, Context<Player> context) {
-        HashMap<String, Double> lootWeightMap = new HashMap<>();
-        for (ConditionalElement<List<Pair<String, BiFunction<Context<Player>, Double, Double>>>, Player> conditionalElement : gameConditions.values()) {
-            modifyWeightMap(lootWeightMap, context, conditionalElement);
+        HashMap<String, Double> gameWeightMap = new HashMap<>();
+        for (ConditionalElement<List<Pair<String, WeightOperation>>, Player> conditionalElement : gameConditions.values()) {
+            modifyWeightMap(gameWeightMap, context, conditionalElement);
         }
-        String gameID = WeightUtils.getRandom(lootWeightMap);
+        String gameID = WeightUtils.getRandom(gameWeightMap);
         return Optional.ofNullable(gameID)
                 .map(id -> getGame(gameID).orElseThrow(() -> new RuntimeException("Could not find game " + gameID)))
                 .orElse(null);
     }
 
-    private void modifyWeightMap(Map<String, Double> weightMap, Context<Player> context, ConditionalElement<List<Pair<String, BiFunction<Context<Player>, Double, Double>>>, Player> conditionalElement) {
+    private void modifyWeightMap(Map<String, Double> weightMap, Context<Player> context, ConditionalElement<List<Pair<String, WeightOperation>>, Player> conditionalElement) {
         if (conditionalElement == null) return;
         if (RequirementManager.isSatisfied(context, conditionalElement.getRequirements())) {
-            for (Pair<String, BiFunction<Context<Player>, Double, Double>> modifierPair : conditionalElement.getElement()) {
+            for (Pair<String, WeightOperation> modifierPair : conditionalElement.getElement()) {
                 double previous = weightMap.getOrDefault(modifierPair.left(), 0d);
-                weightMap.put(modifierPair.left(), modifierPair.right().apply(context, previous));
+                weightMap.put(modifierPair.left(), modifierPair.right().apply(context, previous, weightMap));
             }
-            for (ConditionalElement<List<Pair<String, BiFunction<Context<Player>, Double, Double>>>, Player> sub : conditionalElement.getSubElements().values()) {
+            for (ConditionalElement<List<Pair<String, WeightOperation>>, Player> sub : conditionalElement.getSubElements().values()) {
                 modifyWeightMap(weightMap, context, sub);
             }
         }
diff --git a/core/src/main/java/net/momirealms/customfishing/bukkit/integration/BukkitIntegrationManager.java b/core/src/main/java/net/momirealms/customfishing/bukkit/integration/BukkitIntegrationManager.java
index 468a8943..5d49b350 100644
--- a/core/src/main/java/net/momirealms/customfishing/bukkit/integration/BukkitIntegrationManager.java
+++ b/core/src/main/java/net/momirealms/customfishing/bukkit/integration/BukkitIntegrationManager.java
@@ -39,7 +39,6 @@ import net.momirealms.customfishing.bukkit.integration.region.WorldGuardRegion;
 import net.momirealms.customfishing.bukkit.integration.season.AdvancedSeasonsProvider;
 import net.momirealms.customfishing.bukkit.integration.season.CustomCropsSeasonProvider;
 import net.momirealms.customfishing.bukkit.integration.season.RealisticSeasonsProvider;
-import net.momirealms.customfishing.bukkit.integration.shop.ShopGUICFItemProvider;
 import net.momirealms.customfishing.bukkit.integration.shop.ShopGUIHook;
 import net.momirealms.customfishing.bukkit.item.BukkitItemManager;
 import net.momirealms.customfishing.common.util.Pair;
diff --git a/core/src/main/java/net/momirealms/customfishing/bukkit/loot/BukkitLootManager.java b/core/src/main/java/net/momirealms/customfishing/bukkit/loot/BukkitLootManager.java
index f3a7686b..5591c69a 100644
--- a/core/src/main/java/net/momirealms/customfishing/bukkit/loot/BukkitLootManager.java
+++ b/core/src/main/java/net/momirealms/customfishing/bukkit/loot/BukkitLootManager.java
@@ -24,6 +24,7 @@ import net.momirealms.customfishing.api.mechanic.context.Context;
 import net.momirealms.customfishing.api.mechanic.effect.Effect;
 import net.momirealms.customfishing.api.mechanic.loot.Loot;
 import net.momirealms.customfishing.api.mechanic.loot.LootManager;
+import net.momirealms.customfishing.api.mechanic.loot.operation.WeightOperation;
 import net.momirealms.customfishing.api.mechanic.requirement.ConditionalElement;
 import net.momirealms.customfishing.api.mechanic.requirement.RequirementManager;
 import net.momirealms.customfishing.common.util.Pair;
@@ -34,7 +35,6 @@ import org.jetbrains.annotations.Nullable;
 
 import java.io.File;
 import java.util.*;
-import java.util.function.BiFunction;
 
 @SuppressWarnings("DuplicatedCode")
 public class BukkitLootManager implements LootManager {
@@ -42,7 +42,7 @@ public class BukkitLootManager implements LootManager {
     private final BukkitCustomFishingPlugin plugin;
     private final HashMap<String, Loot> lootMap = new HashMap<>();
     private final HashMap<String, List<String>> groupMembersMap = new HashMap<>();
-    private final LinkedHashMap<String, ConditionalElement<List<Pair<String, BiFunction<Context<Player>, Double, Double>>>, Player>> lootConditions = new LinkedHashMap<>();
+    private final LinkedHashMap<String, ConditionalElement<List<Pair<String, WeightOperation>>, Player>> lootConditions = new LinkedHashMap<>();
 
     public BukkitLootManager(BukkitCustomFishingPlugin plugin) {
         this.plugin = plugin;
@@ -73,23 +73,23 @@ public class BukkitLootManager implements LootManager {
         }
     }
 
-    private ConditionalElement<List<Pair<String, BiFunction<Context<Player>, Double, Double>>>, Player> parseLootConditions(Section section) {
+    private ConditionalElement<List<Pair<String, WeightOperation>>, Player> parseLootConditions(Section section) {
         Section subSection = section.getSection("sub-groups");
         if (subSection == null) {
             return new ConditionalElement<>(
-                    plugin.getConfigManager().parseWeightOperation(section.getStringList("list")),
+                    plugin.getConfigManager().parseWeightOperation(section.getStringList("list"), (id) -> getLoot(id).isPresent()),
                     Map.of(),
                     plugin.getRequirementManager().parseRequirements(section.getSection("conditions"), false)
             );
         } else {
-            HashMap<String, ConditionalElement<List<Pair<String, BiFunction<Context<Player>, Double, Double>>>, Player>> subElements = new HashMap<>();
+            HashMap<String, ConditionalElement<List<Pair<String, WeightOperation>>, Player>> subElements = new HashMap<>();
             for (Map.Entry<String, Object> entry : subSection.getStringRouteMappedValues(false).entrySet()) {
                 if (entry.getValue() instanceof Section innerSection) {
                     subElements.put(entry.getKey(), parseLootConditions(innerSection));
                 }
             }
             return new ConditionalElement<>(
-                    plugin.getConfigManager().parseWeightOperation(section.getStringList("list")),
+                    plugin.getConfigManager().parseWeightOperation(section.getStringList("list"), (id) -> getLoot(id).isPresent()),
                     subElements,
                     plugin.getRequirementManager().parseRequirements(section.getSection("conditions"), false)
             );
@@ -136,18 +136,18 @@ public class BukkitLootManager implements LootManager {
     @Override
     public HashMap<String, Double> getWeightedLoots(Effect effect, Context<Player> context) {
         HashMap<String, Double> lootWeightMap = new HashMap<>();
-        for (ConditionalElement<List<Pair<String, BiFunction<Context<Player>, Double, Double>>>, Player> conditionalElement : lootConditions.values()) {
+        for (ConditionalElement<List<Pair<String, WeightOperation>>, Player> conditionalElement : lootConditions.values()) {
             modifyWeightMap(lootWeightMap, context, conditionalElement);
         }
-        for (Pair<String, BiFunction<Context<Player>, Double, Double>> pair : effect.weightOperations()) {
+        for (Pair<String, WeightOperation> pair : effect.weightOperations()) {
             Double previous = lootWeightMap.get(pair.left());
             if (previous != null) {
-                lootWeightMap.put(pair.left(), pair.right().apply(context, previous));
+                lootWeightMap.put(pair.left(), pair.right().apply(context, previous, lootWeightMap));
             }
         }
-        for (Pair<String, BiFunction<Context<Player>, Double, Double>> pair : effect.weightOperationsIgnored()) {
+        for (Pair<String, WeightOperation> pair : effect.weightOperationsIgnored()) {
             double previous = lootWeightMap.getOrDefault(pair.left(), 0d);
-            lootWeightMap.put(pair.left(), pair.right().apply(context, previous));
+            lootWeightMap.put(pair.left(), pair.right().apply(context, previous, lootWeightMap));
         }
         return lootWeightMap;
     }
@@ -155,36 +155,36 @@ public class BukkitLootManager implements LootManager {
     @Nullable
     @Override
     public Loot getNextLoot(Effect effect, Context<Player> context) {
-        HashMap<String, Double> lootWeightMap = new HashMap<>();
-        for (ConditionalElement<List<Pair<String, BiFunction<Context<Player>, Double, Double>>>, Player> conditionalElement : lootConditions.values()) {
-            modifyWeightMap(lootWeightMap, context, conditionalElement);
+        HashMap<String, Double> weightMap = new HashMap<>();
+        for (ConditionalElement<List<Pair<String, WeightOperation>>, Player> conditionalElement : lootConditions.values()) {
+            modifyWeightMap(weightMap, context, conditionalElement);
         }
-        for (Pair<String, BiFunction<Context<Player>, Double, Double>> pair : effect.weightOperations()) {
-            Double previous = lootWeightMap.get(pair.left());
+        for (Pair<String, WeightOperation> pair : effect.weightOperations()) {
+            Double previous = weightMap.get(pair.left());
             if (previous != null) {
-                lootWeightMap.put(pair.left(), pair.right().apply(context, previous));
+                weightMap.put(pair.left(), pair.right().apply(context, previous, weightMap));
             }
         }
-        for (Pair<String, BiFunction<Context<Player>, Double, Double>> pair : effect.weightOperationsIgnored()) {
-            double previous = lootWeightMap.getOrDefault(pair.left(), 0d);
-            lootWeightMap.put(pair.left(), pair.right().apply(context, previous));
+        for (Pair<String, WeightOperation> pair : effect.weightOperationsIgnored()) {
+            double previous = weightMap.getOrDefault(pair.left(), 0d);
+            weightMap.put(pair.left(), pair.right().apply(context, previous, weightMap));
         }
 
-        plugin.debug(lootWeightMap);
-        String lootID = WeightUtils.getRandom(lootWeightMap);
+        plugin.debug(weightMap::toString);
+        String lootID = WeightUtils.getRandom(weightMap);
         return Optional.ofNullable(lootID)
                 .map(id -> getLoot(lootID).orElseThrow(() -> new NullPointerException("Could not find loot " + lootID)))
                 .orElse(null);
     }
 
-    private void modifyWeightMap(Map<String, Double> weightMap, Context<Player> context, ConditionalElement<List<Pair<String, BiFunction<Context<Player>, Double, Double>>>, Player> conditionalElement) {
+    private void modifyWeightMap(Map<String, Double> weightMap, Context<Player> context, ConditionalElement<List<Pair<String, WeightOperation>>, Player> conditionalElement) {
         if (conditionalElement == null) return;
         if (RequirementManager.isSatisfied(context, conditionalElement.getRequirements())) {
-            for (Pair<String, BiFunction<Context<Player>, Double, Double>> modifierPair : conditionalElement.getElement()) {
+            for (Pair<String, WeightOperation> modifierPair : conditionalElement.getElement()) {
                 double previous = weightMap.getOrDefault(modifierPair.left(), 0d);
-                weightMap.put(modifierPair.left(), modifierPair.right().apply(context, previous));
+                weightMap.put(modifierPair.left(), modifierPair.right().apply(context, previous, weightMap));
             }
-            for (ConditionalElement<List<Pair<String, BiFunction<Context<Player>, Double, Double>>>, Player> sub : conditionalElement.getSubElements().values()) {
+            for (ConditionalElement<List<Pair<String, WeightOperation>>, Player> sub : conditionalElement.getSubElements().values()) {
                 modifyWeightMap(weightMap, context, sub);
             }
         }
diff --git a/gradle.properties b/gradle.properties
index 5f349b19..96ae5874 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,6 +1,6 @@
 # Project settings
 # Rule: [major update].[feature update].[bug fix]
-project_version=2.2.36
+project_version=2.3.0
 config_version=38
 project_group=net.momirealms
 
@@ -46,9 +46,9 @@ guava_version=33.3.1-jre
 lz4_version=1.8.0
 
 # Proxy settings
-#systemProp.socks.proxyHost=127.0.0.1
-#systemProp.socks.proxyPort=7890
-#systemProp.http.proxyHost=127.0.0.1
-#systemProp.http.proxyPort=7890
-#systemProp.https.proxyHost=127.0.0.1
-#systemProp.https.proxyPort=7890
\ No newline at end of file
+systemProp.socks.proxyHost=127.0.0.1
+systemProp.socks.proxyPort=7890
+systemProp.http.proxyHost=127.0.0.1
+systemProp.http.proxyPort=7890
+systemProp.https.proxyHost=127.0.0.1
+systemProp.https.proxyPort=7890
\ No newline at end of file