diff --git a/Reactor/Networking/Attributes/MethodRpcAttribute.cs b/Reactor/Networking/Attributes/MethodRpcAttribute.cs
index bd5dc8a..5819752 100644
--- a/Reactor/Networking/Attributes/MethodRpcAttribute.cs
+++ b/Reactor/Networking/Attributes/MethodRpcAttribute.cs
@@ -33,6 +33,12 @@ public sealed class MethodRpcAttribute : Attribute
     /// </summary>
     public RpcLocalHandling LocalHandling { get; set; } = RpcLocalHandling.Before;
 
+    /// <summary>
+    /// Gets or sets a value indicating whether the rpc should be sent immediately.
+    /// </summary>
+    [Obsolete("Non-immediate RPCs were removed in 2025.5.20. All RPCs are immediate. This property will be removed in a future version.")]
+    public bool SendImmediately { get; set; }
+
     /// <summary>
     /// Initializes a new instance of the <see cref="MethodRpcAttribute"/> class.
     /// </summary>
@@ -66,7 +72,7 @@ public sealed class MethodRpcAttribute : Attribute
 
             try
             {
-                var customRpc = new MethodRpc(plugin, method, attribute.Id, attribute.SendOption, attribute.LocalHandling);
+                var customRpc = new MethodRpc(plugin, method, attribute.Id, attribute.SendOption, attribute.LocalHandling, attribute.SendImmediately);
                 PluginSingleton<ReactorPlugin>.Instance.CustomRpcManager.Register(customRpc);
             }
             catch (Exception e)
diff --git a/Reactor/Networking/Rpc/CustomRpc.cs b/Reactor/Networking/Rpc/CustomRpc.cs
index 38aac99..fe161eb 100644
--- a/Reactor/Networking/Rpc/CustomRpc.cs
+++ b/Reactor/Networking/Rpc/CustomRpc.cs
@@ -56,10 +56,11 @@ public abstract class CustomRpc<TPlugin, TInnerNetObject, TData> : UnsafeCustomR
     /// </summary>
     /// <param name="innerNetObject">The <see cref="InnerNetObject"/> to send the rpc on.</param>
     /// <param name="data">The data to send.</param>
+    /// <param name="immediately">Whether to send it immediately.</param>
     /// <param name="ackCallback">The callback to invoke when this packet is acknowledged.</param>
-    public void Send(InnerNetObject innerNetObject, TData data, Action? ackCallback = null)
+    public void Send(InnerNetObject innerNetObject, TData data, bool immediately = false, Action? ackCallback = null)
     {
-        UnsafeSend(innerNetObject, data, ackCallback: ackCallback);
+        UnsafeSend(innerNetObject, data, immediately, ackCallback: ackCallback);
     }
 
     /// <summary>
@@ -71,7 +72,7 @@ public abstract class CustomRpc<TPlugin, TInnerNetObject, TData> : UnsafeCustomR
     /// <param name="ackCallback">The callback to invoke when this packet is acknowledged.</param>
     public void SendTo(InnerNetObject innerNetObject, int targetClientId, TData data, Action? ackCallback = null)
     {
-        UnsafeSend(innerNetObject, data, targetClientId, ackCallback);
+        UnsafeSend(innerNetObject, data, true, targetClientId, ackCallback);
     }
 }
 
@@ -120,10 +121,11 @@ public abstract class CustomRpc<TPlugin, TInnerNetObject> : UnsafeCustomRpc wher
     /// Sends this custom rpc on the specified <paramref name="innerNetObject"/>.
     /// </summary>
     /// <param name="innerNetObject">The <see cref="InnerNetObject"/> to send the rpc on.</param>
+    /// <param name="immediately">Whether to send it immediately.</param>
     /// <param name="ackCallback">The callback to invoke when this packet is acknowledged.</param>
-    public void Send(InnerNetObject innerNetObject, Action? ackCallback = null)
+    public void Send(InnerNetObject innerNetObject, bool immediately = false, Action? ackCallback = null)
     {
-        UnsafeSend(innerNetObject, ackCallback);
+        UnsafeSend(innerNetObject, immediately, ackCallback: ackCallback);
     }
 
     /// <summary>
@@ -134,6 +136,6 @@ public abstract class CustomRpc<TPlugin, TInnerNetObject> : UnsafeCustomRpc wher
     /// <param name="ackCallback">The callback to invoke when this packet is acknowledged.</param>
     public void SendTo(InnerNetObject innerNetObject, int targetClientId, Action? ackCallback = null)
     {
-        UnsafeSend(innerNetObject, null, targetClientId, ackCallback);
+        UnsafeSend(innerNetObject, null, true, targetClientId, ackCallback);
     }
 }
diff --git a/Reactor/Networking/Rpc/MethodRpc.cs b/Reactor/Networking/Rpc/MethodRpc.cs
index 3f1bd61..dbf66f7 100644
--- a/Reactor/Networking/Rpc/MethodRpc.cs
+++ b/Reactor/Networking/Rpc/MethodRpc.cs
@@ -32,11 +32,13 @@ public class MethodRpc : UnsafeCustomRpc
     /// <param name="id">The id of the rpc.</param>
     /// <param name="option">The send option of the rpc.</param>
     /// <param name="localHandling">The local handling method of the rpc.</param>
-    public MethodRpc(BasePlugin plugin, MethodInfo method, uint id, SendOption option, RpcLocalHandling localHandling) : base(plugin, id)
+    /// <param name="sendImmediately">The value indicating whether the rpc should be sent immediately.</param>
+    public MethodRpc(BasePlugin plugin, MethodInfo method, uint id, SendOption option, RpcLocalHandling localHandling, bool sendImmediately) : base(plugin, id)
     {
         Method = method;
         LocalHandling = localHandling;
         SendOption = option;
+        SendImmediately = sendImmediately;
 
         var parameters = method.GetParameters();
 
@@ -86,6 +88,12 @@ public class MethodRpc : UnsafeCustomRpc
     /// <inheritdoc />
     public override SendOption SendOption { get; }
 
+    /// <summary>
+    /// Gets a value indicating whether the method rpc should be sent immediately.
+    /// </summary>
+    [Obsolete("Non-immediate RPCs were removed in 2025.5.20. All RPCs are immediate. This property will be removed in a future version.")]
+    public bool SendImmediately { get; }
+
     /// <inheritdoc />
     public override void UnsafeWrite(MessageWriter writer, object? data)
     {
@@ -127,7 +135,7 @@ public class MethodRpc : UnsafeCustomRpc
     /// <param name="args">The arguments to serialize and send.</param>
     public void Send(InnerNetObject innerNetObject, object[] args)
     {
-        UnsafeSend(innerNetObject, args);
+        UnsafeSend(innerNetObject, args, SendImmediately);
     }
 
     private static readonly MethodInfo _sendMethod = AccessTools.Method(typeof(MethodRpc), nameof(Send));
diff --git a/Reactor/Networking/Rpc/PlayerCustomRpc.cs b/Reactor/Networking/Rpc/PlayerCustomRpc.cs
index 77b2684..47c9d8a 100644
--- a/Reactor/Networking/Rpc/PlayerCustomRpc.cs
+++ b/Reactor/Networking/Rpc/PlayerCustomRpc.cs
@@ -19,10 +19,11 @@ public abstract class PlayerCustomRpc<TPlugin, TData> : CustomRpc<TPlugin, Playe
     /// Sends this custom rpc on the local player with the specified <paramref name="data"/>.
     /// </summary>
     /// <param name="data">The data to send.</param>
+    /// <param name="immediately">Whether to send it immediately.</param>
     /// <param name="ackCallback">The callback to invoke when this packet is acknowledged.</param>
-    public void Send(TData data, Action? ackCallback = null)
+    public void Send(TData data, bool immediately = false, Action? ackCallback = null)
     {
-        Send(PlayerControl.LocalPlayer, data, ackCallback);
+        Send(PlayerControl.LocalPlayer, data, immediately, ackCallback);
     }
 
     /// <summary>
@@ -51,10 +52,11 @@ public abstract class PlayerCustomRpc<TPlugin> : CustomRpc<TPlugin, PlayerContro
     /// <summary>
     /// Sends this custom rpc on the local player.
     /// </summary>
+    /// <param name="immediately">Whether to send it immediately.</param>
     /// <param name="ackCallback">The callback to invoke when this packet is acknowledged.</param>
-    public void Send(Action? ackCallback = null)
+    public void Send(bool immediately = false, Action? ackCallback = null)
     {
-        Send(PlayerControl.LocalPlayer, ackCallback);
+        Send(PlayerControl.LocalPlayer, immediately, ackCallback);
     }
 
     /// <summary>
diff --git a/Reactor/Networking/Rpc/UnsafeCustomRpc.cs b/Reactor/Networking/Rpc/UnsafeCustomRpc.cs
index 3a7d65a..67fefb4 100644
--- a/Reactor/Networking/Rpc/UnsafeCustomRpc.cs
+++ b/Reactor/Networking/Rpc/UnsafeCustomRpc.cs
@@ -91,9 +91,10 @@ public abstract class UnsafeCustomRpc
     /// </summary>
     /// <param name="innerNetObject">The <see cref="InnerNetObject"/> to send the rpc on.</param>
     /// <param name="data">The data to send.</param>
+    /// <param name="immediately">Whether to send it immediately.</param>
     /// <param name="targetClientId">Target client id, defaults to broadcast.</param>
     /// <param name="ackCallback">The callback to invoke when this packet is acknowledged.</param>
-    public void UnsafeSend(InnerNetObject innerNetObject, object? data, int targetClientId = -1, Action? ackCallback = null)
+    public void UnsafeSend(InnerNetObject innerNetObject, object? data, bool immediately = false, int targetClientId = -1, Action? ackCallback = null)
     {
         ArgumentNullException.ThrowIfNull(innerNetObject);
 
@@ -107,7 +108,16 @@ public abstract class UnsafeCustomRpc
             UnsafeHandle(innerNetObject, data);
         }
 
-        var writer = AmongUsClient.Instance.StartRpcImmediately(innerNetObject.NetId, CustomRpcManager.CallId, SendOption, targetClientId);
+        if (immediately == false)
+        {
+            Warning("Non-immediate RPCs were removed in 2025.5.20! Reactor will now always send immediately!");
+        }
+
+        var writer = AmongUsClient.Instance.StartRpcImmediately(
+            innerNetObject.NetId,
+            CustomRpcManager.CallId,
+            SendOption,
+            targetClientId);
 
         writer.Write(Mod);
         writer.WritePacked(Id);