diff --git a/core/src/mindustry/core/NetServer.java b/core/src/mindustry/core/NetServer.java
index 9fead5492b..844447e7b8 100644
--- a/core/src/mindustry/core/NetServer.java
+++ b/core/src/mindustry/core/NetServer.java
@@ -230,7 +230,11 @@ public class NetServer implements ApplicationListener{
 
         net.handleServer(InvokePacket.class, (con, packet) -> {
             if(con.player == null) return;
-            RemoteReadServer.readPacket(packet.writeBuffer, packet.type, con.player);
+            try{
+                RemoteReadServer.readPacket(packet.writeBuffer, packet.type, con.player);
+            }catch(ValidateException e){
+                Log.debug("Validation failed for '{0}': {1}", e.player, e.getMessage());
+            }
         });
 
         registerCommands();
@@ -504,6 +508,7 @@ public class NetServer implements ApplicationListener{
         player.isShooting = shooting;
         player.isBuilding = building;
         player.buildQueue().clear();
+
         for(BuildRequest req : requests){
             if(req == null) continue;
             Tile tile = world.tile(req.x, req.y);
@@ -513,10 +518,23 @@ public class NetServer implements ApplicationListener{
                 continue;
             }else if(!req.breaking && tile.block() == req.block && (!req.block.rotate || tile.rotation() == req.rotation)){
                 continue;
+            }else if(connection.rejectedRequests.contains(r -> r.breaking == req.breaking && r.x == req.x && r.y == req.y)){ //check if request was recently rejected, and skip it if so
+                continue;
+            }else if(!netServer.admins.allowAction(player, req.breaking ? ActionType.breakBlock : ActionType.placeBlock, tile, action -> { //make sure request is allowed by the server
+                action.block = req.block;
+                action.rotation = req.rotation;
+                action.config = req.config;
+            })){
+                //force the player to remove this request if that's not the case
+                Call.removeQueueBlock(player.con, req.x, req.y, req.breaking);
+                connection.rejectedRequests.add(req);
+                continue;
             }
             player.buildQueue().addLast(req);
         }
 
+        connection.rejectedRequests.clear();
+
         vector.set(x - player.getInterpolator().target.x, y - player.getInterpolator().target.y);
         vector.limit(maxMove);
 
diff --git a/core/src/mindustry/entities/TargetPriority.java b/core/src/mindustry/entities/TargetPriority.java
index ec36b03925..583710ca2c 100644
--- a/core/src/mindustry/entities/TargetPriority.java
+++ b/core/src/mindustry/entities/TargetPriority.java
@@ -1,5 +1,6 @@
 package mindustry.entities;
 
+/** A higher ordinal means a higher priority. Higher priority blocks will always get targeted over those of lower priority, regardless of distance. */
 public enum TargetPriority{
     base,
     turret
diff --git a/core/src/mindustry/entities/traits/BuilderTrait.java b/core/src/mindustry/entities/traits/BuilderTrait.java
index 02ae0bca5b..570f5eabf9 100644
--- a/core/src/mindustry/entities/traits/BuilderTrait.java
+++ b/core/src/mindustry/entities/traits/BuilderTrait.java
@@ -67,9 +67,9 @@ public interface BuilderTrait extends Entity, TeamTrait{
 
         if(!(tile.block() instanceof BuildBlock)){
             if(!current.initialized && canCreateBlocks() && !current.breaking && Build.validPlace(getTeam(), current.x, current.y, current.block, current.rotation)){
-                Call.beginPlace(getTeam(), current.x, current.y, current.block, current.rotation);
+                Build.beginPlace(getTeam(), current.x, current.y, current.block, current.rotation);
             }else if(!current.initialized && canCreateBlocks() && current.breaking && Build.validBreak(getTeam(), current.x, current.y)){
-                Call.beginBreak(getTeam(), current.x, current.y);
+                Build.beginBreak(getTeam(), current.x, current.y);
             }else{
                 buildQueue().removeFirst();
                 return;
@@ -118,6 +118,14 @@ public interface BuilderTrait extends Entity, TeamTrait{
         return request.stuck && !core.items.has(request.block.requirements);
     }
 
+    default void removeRequest(int x, int y, boolean breaking){
+        //remove matching request
+        int idx = player.buildQueue().indexOf(req -> req.breaking == breaking && req.x == x && req.y == y);
+        if(idx != -1){
+            player.buildQueue().removeIndex(idx);
+        }
+    }
+
     /** Returns the queue for storing build requests. */
     Queue<BuildRequest> buildQueue();
 
diff --git a/core/src/mindustry/game/GlobalData.java b/core/src/mindustry/game/GlobalData.java
index 3dbf592a71..0e72ef7245 100644
--- a/core/src/mindustry/game/GlobalData.java
+++ b/core/src/mindustry/game/GlobalData.java
@@ -85,9 +85,15 @@ public class GlobalData{
         if(amount > 0){
             unlockContent(item);
         }
+        amount = Math.max(amount, 0);
+
         modified = true;
         items.getAndIncrement(item, 0, amount);
         state.stats.itemsDelivered.getAndIncrement(item, 0, amount);
+
+        //clamp overflow
+        if(items.get(item, 0) < 0) items.put(item, Integer.MAX_VALUE);
+        if(state.stats.itemsDelivered.get(item, 0) < 0) state.stats.itemsDelivered.put(item, Integer.MAX_VALUE);
     }
 
     public boolean hasItems(Array<ItemStack> stacks){
diff --git a/core/src/mindustry/input/InputHandler.java b/core/src/mindustry/input/InputHandler.java
index e56244928e..8000fc4e19 100644
--- a/core/src/mindustry/input/InputHandler.java
+++ b/core/src/mindustry/input/InputHandler.java
@@ -1,8 +1,6 @@
 package mindustry.input;
 
 import arc.*;
-import mindustry.annotations.Annotations.*;
-import arc.struct.*;
 import arc.func.*;
 import arc.graphics.*;
 import arc.graphics.g2d.*;
@@ -13,8 +11,10 @@ import arc.math.geom.*;
 import arc.scene.*;
 import arc.scene.event.*;
 import arc.scene.ui.layout.*;
+import arc.struct.*;
 import arc.util.ArcAnnotate.*;
 import arc.util.*;
+import mindustry.annotations.Annotations.*;
 import mindustry.content.*;
 import mindustry.entities.*;
 import mindustry.entities.effect.*;
@@ -27,12 +27,13 @@ import mindustry.gen.*;
 import mindustry.graphics.*;
 import mindustry.input.Placement.*;
 import mindustry.net.*;
+import mindustry.net.Administration.*;
 import mindustry.type.*;
 import mindustry.ui.fragments.*;
 import mindustry.world.*;
 import mindustry.world.blocks.*;
 import mindustry.world.blocks.BuildBlock.*;
-import mindustry.world.blocks.power.PowerNode;
+import mindustry.world.blocks.power.*;
 
 import java.util.*;
 
@@ -66,6 +67,11 @@ public abstract class InputHandler implements InputProcessor, GestureListener{
 
     //methods to override
 
+    @Remote(variants = Variant.one)
+    public static void removeQueueBlock(int x, int y, boolean breaking){
+        player.removeRequest(x, y, breaking);
+    }
+
     @Remote(targets = Loc.client, called = Loc.server)
     public static void dropItem(Player player, float angle){
         if(net.server() && player.item().amount <= 0){
@@ -78,8 +84,9 @@ public abstract class InputHandler implements InputProcessor, GestureListener{
 
     @Remote(targets = Loc.both, called = Loc.server, forward = true, unreliable = true)
     public static void rotateBlock(Player player, Tile tile, boolean direction){
-        if(net.server() && !Units.canInteract(player, tile)){
-            throw new ValidateException(player, "Player cannot drop an item.");
+        if(net.server() && (!Units.canInteract(player, tile) ||
+            !netServer.admins.allowAction(player, ActionType.rotate, tile, action -> action.rotation = Mathf.mod(tile.rotation() + Mathf.sign(direction), 4)))){
+            throw new ValidateException(player, "Player cannot rotate a block.");
         }
 
         tile.rotation(Mathf.mod(tile.rotation() + Mathf.sign(direction), 4));
@@ -93,7 +100,11 @@ public abstract class InputHandler implements InputProcessor, GestureListener{
     @Remote(targets = Loc.both, forward = true, called = Loc.server)
     public static void transferInventory(Player player, Tile tile){
         if(player == null || player.timer == null) return;
-        if(net.server() && (player.item().amount <= 0 || player.isTransferring|| !Units.canInteract(player, tile))){
+        if(net.server() && (player.item().amount <= 0 || player.isTransferring|| !Units.canInteract(player, tile) ||
+            !netServer.admins.allowAction(player, ActionType.depositItem, tile, action -> {
+                action.itemAmount = player.item().amount;
+                action.item = player.item().item;
+            }))){
             throw new ValidateException(player, "Player cannot transfer an item.");
         }
 
@@ -143,14 +154,18 @@ public abstract class InputHandler implements InputProcessor, GestureListener{
     @Remote(targets = Loc.both, called = Loc.server, forward = true)
     public static void onTileTapped(Player player, Tile tile){
         if(tile == null || player == null) return;
-        if(!Units.canInteract(player, tile)) return;
+        if(net.server() && (!Units.canInteract(player, tile) ||
+            !netServer.admins.allowAction(player, ActionType.tapTile, tile, action -> {}))) throw new ValidateException(player, "Player cannot tap a tile.");
         tile.block().tapped(tile, player);
         Core.app.post(() -> Events.fire(new TapEvent(tile, player)));
     }
 
     @Remote(targets = Loc.both, called = Loc.both, forward = true)
     public static void onTileConfig(Player player, Tile tile, int value){
-        if(tile == null || !Units.canInteract(player, tile)) return;
+        if(tile == null) return;
+
+        if(net.server() && (!Units.canInteract(player, tile) ||
+            !netServer.admins.allowAction(player, ActionType.configure, tile, action -> action.config = value))) throw new ValidateException(player, "Player cannot configure a tile.");
         tile.block().configured(tile, player, value);
         Core.app.post(() -> Events.fire(new TapConfigEvent(tile, player, value)));
     }
diff --git a/core/src/mindustry/net/Administration.java b/core/src/mindustry/net/Administration.java
index aa36705c39..8a5a438e14 100644
--- a/core/src/mindustry/net/Administration.java
+++ b/core/src/mindustry/net/Administration.java
@@ -529,6 +529,10 @@ public class Administration{
         public @NonNull ActionType type;
         public @NonNull Tile tile;
 
+        /** valid for block placement events only */
+        public @Nullable Block block;
+        public int rotation;
+
         /** valid for configure and rotation-type events only. */
         public int config;
 
@@ -554,7 +558,7 @@ public class Administration{
     }
 
     public enum ActionType{
-        breakBlock, placeBlock, rotate, configure, withdrawItem, depositItem
+        breakBlock, placeBlock, rotate, configure, tapTile, withdrawItem, depositItem
     }
 
 }
diff --git a/core/src/mindustry/net/ArcNetProvider.java b/core/src/mindustry/net/ArcNetProvider.java
index 19ce42e48e..68fc3a08a4 100644
--- a/core/src/mindustry/net/ArcNetProvider.java
+++ b/core/src/mindustry/net/ArcNetProvider.java
@@ -114,12 +114,7 @@ public class ArcNetProvider implements NetProvider{
                     try{
                         net.handleServerReceived(k, object);
                     }catch(RuntimeException e){
-                        if(e.getCause() instanceof ValidateException){
-                            ValidateException v = (ValidateException)e.getCause();
-                            Log.err("Validation failed: {0} ({1})", v.player.name, v.getMessage());
-                        }else{
-                            e.printStackTrace();
-                        }
+                        e.printStackTrace();
                     }catch(Exception e){
                         e.printStackTrace();
                     }
diff --git a/core/src/mindustry/net/NetConnection.java b/core/src/mindustry/net/NetConnection.java
index 104ed2d431..6555957b5b 100644
--- a/core/src/mindustry/net/NetConnection.java
+++ b/core/src/mindustry/net/NetConnection.java
@@ -1,7 +1,9 @@
 package mindustry.net;
 
-import arc.util.*;
+import arc.struct.*;
 import arc.util.ArcAnnotate.*;
+import arc.util.*;
+import mindustry.entities.traits.BuilderTrait.*;
 import mindustry.entities.type.*;
 import mindustry.gen.*;
 import mindustry.net.Administration.*;
@@ -21,6 +23,8 @@ public abstract class NetConnection{
     public int lastRecievedClientSnapshot = -1;
     /** Timestamp of last recieved snapshot. */
     public long lastRecievedClientTime;
+    /** Build requests that have been recently rejected. This is cleared every snapshot. */
+    public Array<BuildRequest> rejectedRequests = new Array<>();
 
     public boolean hasConnected, hasBegunConnecting, hasDisconnected;
     public float viewWidth, viewHeight, viewX, viewY;
diff --git a/core/src/mindustry/ui/fragments/BlockInventoryFragment.java b/core/src/mindustry/ui/fragments/BlockInventoryFragment.java
index ce2a83e5d4..926c56460a 100644
--- a/core/src/mindustry/ui/fragments/BlockInventoryFragment.java
+++ b/core/src/mindustry/ui/fragments/BlockInventoryFragment.java
@@ -1,8 +1,6 @@
 package mindustry.ui.fragments;
 
 import arc.*;
-import mindustry.annotations.Annotations.*;
-import arc.struct.*;
 import arc.func.*;
 import arc.graphics.g2d.*;
 import arc.input.*;
@@ -13,14 +11,18 @@ import arc.scene.actions.*;
 import arc.scene.event.*;
 import arc.scene.ui.*;
 import arc.scene.ui.layout.*;
+import arc.struct.*;
 import arc.util.*;
+import mindustry.annotations.Annotations.*;
 import mindustry.core.GameState.*;
 import mindustry.entities.*;
 import mindustry.entities.type.*;
 import mindustry.game.EventType.*;
 import mindustry.gen.*;
+import mindustry.net.Administration.*;
+import mindustry.net.*;
 import mindustry.type.*;
-import mindustry.ui.Cicon;
+import mindustry.ui.*;
 import mindustry.world.*;
 
 import static mindustry.Vars.*;
@@ -37,8 +39,14 @@ public class BlockInventoryFragment extends Fragment{
     @Remote(called = Loc.server, targets = Loc.both, forward = true)
     public static void requestItem(Player player, Tile tile, Item item, int amount){
         if(player == null || tile == null || !tile.interactable(player.getTeam())) return;
-        if(!Units.canInteract(player, tile)) return;
         amount = Mathf.clamp(amount, 0, player.getItemCapacity());
+        int fa = amount;
+
+        if(net.server() && (!Units.canInteract(player, tile) ||
+            !netServer.admins.allowAction(player, ActionType.withdrawItem, tile, action -> {
+                action.item = item;
+                action.itemAmount = fa;
+            }))) throw new ValidateException(player, "Player cannot request items.");
 
         int removed = tile.block().removeStack(tile, item, amount);
 
diff --git a/core/src/mindustry/world/Build.java b/core/src/mindustry/world/Build.java
index b8d41df4f0..1e20da65e8 100644
--- a/core/src/mindustry/world/Build.java
+++ b/core/src/mindustry/world/Build.java
@@ -1,17 +1,15 @@
 package mindustry.world;
 
-import mindustry.annotations.Annotations.Loc;
-import mindustry.annotations.Annotations.Remote;
-import arc.Core;
-import arc.Events;
-import arc.math.Mathf;
+import arc.*;
+import arc.math.*;
 import arc.math.geom.*;
-import mindustry.content.Blocks;
-import mindustry.entities.Units;
-import mindustry.game.EventType.BlockBuildBeginEvent;
-import mindustry.game.Team;
-import mindustry.world.blocks.BuildBlock;
-import mindustry.world.blocks.BuildBlock.BuildEntity;
+import mindustry.annotations.Annotations.*;
+import mindustry.content.*;
+import mindustry.entities.*;
+import mindustry.game.EventType.*;
+import mindustry.game.*;
+import mindustry.world.blocks.*;
+import mindustry.world.blocks.BuildBlock.*;
 
 import static mindustry.Vars.*;
 
diff --git a/desktop/src/mindustry/desktop/steam/SNet.java b/desktop/src/mindustry/desktop/steam/SNet.java
index cb23befebe..e27a9d8c52 100644
--- a/desktop/src/mindustry/desktop/steam/SNet.java
+++ b/desktop/src/mindustry/desktop/steam/SNet.java
@@ -76,14 +76,7 @@ public class SNet implements SteamNetworkingCallback, SteamMatchmakingCallback,
                                 }
 
                                 net.handleServerReceived(con, output);
-                            }catch(RuntimeException e){
-                                if(e.getCause() instanceof ValidateException){
-                                    ValidateException v = (ValidateException)e.getCause();
-                                    Log.err("Validation failed: {0} ({1})", v.player.name, v.getMessage());
-                                }else{
-                                    Log.err(e);
-                                }
-                            }catch(Exception e){
+                            }catch(Throwable e){
                                 Log.err(e);
                             }
                         }else if(currentServer != null && fromID == currentServer.getAccountID()){
diff --git a/gradle.properties b/gradle.properties
index 65d5d065a3..091723c9aa 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,3 +1,3 @@
 org.gradle.daemon=true
 org.gradle.jvmargs=-Xms256m -Xmx1024m
-archash=097f07c939d99020b24a9b33fc3e24bf800e210d
+archash=2be8dfe555b6aa4e5307ce56a92e24d8fee39a0b