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Getting Started

Unity’s default loop forces you to wait. Save a script, sit through a compile, lose Play Mode state, then rebuild the situation you were testing. Hot Patch breaks that cycle.

Edit in your IDE. Save. Keep playing. The change lands on the next time that code runs - often in milliseconds - while your scene, timers, and debug setup stay exactly where you left them.

From install to first live patch

1. Import

Add the package from the Asset Store

2. Start

Accept the license, then press Start

3. Iterate

Enter Play Mode, edit C#, save, and feel it live

Why this matters

Gameplay iteration is usually limited by compile time, not by ideas. Hot Patch is built for the moments that matter most:

  • Tuning jump feel, damage, AI weights, or UI timing without restarting the fight
  • Debugging a rare state you finally reproduced - and keeping it
  • Prototyping in Play Mode instead of planning around reloads

No project rewrite. No special attributes required to get started. Import, start, play.

Open the window

Tools → DivinityCodes → Hot Patch

Tab Role in your workflow
Home Start patching, watch the live log, recompile or sync when you need a full refresh
Options License and fine-tuning - defaults work for most teams
About Version and links

Your first session

Code changes applied without interrupting Play Mode

1. Import

Get the package from the Unity Asset Store and import it into your project.

2. Start Hot Patch

  1. Open Tools → DivinityCodes → Hot Patch
  2. On Options, accept the license
  3. On Home, press Start

Hot Patch is armed. As soon as you enter Play Mode, saves from your IDE become live patches.

3. Edit while playing

  1. Enter Play Mode
  2. Wait for: "Hot Patch is ready - IDE saves will patch at runtime without recompiling."
  3. Change a gameplay script in Rider, Visual Studio, VS Code, or any editor
  4. Save

The new logic runs the next time that method is called. Tweak Update and feel it next frame. Change a button handler and click again.

One-shot Unity messages

Editing Awake or Start updates the method, but Hot Patch will not re-fire those events automatically. Prefer editing code that runs again - or call it yourself. See Unity callbacks.

What happens under the hood (in plain words)

When you save during Play Mode:

  1. Hot Patch sees the file change
  2. It compiles only what changed - not your whole solution
  3. Live method calls are redirected to the new code
  4. Your Play Mode session never domain-reloads

That is why state survives and why the loop feels instant.

Staying in control of Unity’s refresh

Normally, Unity recompiles on every script save and wipes Play Mode. While Hot Patch is running, it holds that auto-refresh so you decide when a full recompile happens.

  • Saves during Play Mode → live patches, state kept
  • Exit Play Mode → patches clear; optionally Unity recompiles so Edit Mode matches disk (on by default)
  • Recompile in the window → full sync from disk without leaving Play Mode when you want it

JetBrains Rider

Disable "Automatically Refresh Assets in Unity" under
Settings → Appearance & Behavior → System Settings
so Rider does not force a domain reload behind Hot Patch’s back.

Rider setting: Automatically Refresh Assets in Unity disabled

When a save does nothing

Sometimes the log shows a save but no patch - usually because the edit was comments-only, the script is under Editor/, or the change type is unsupported. Press Recompile for a full sync, or see Troubleshooting.

Stop when you are done

Press Stop on Home to return Unity to its normal refresh behavior. Exiting Play Mode also clears runtime patches and can request a compile so the Editor stays in sync with disk.

Next steps