D2R Mobile

An open-source iOS / macOS compatibility layer for Diablo II: Resurrected with the Reign of the Warlock expansion. It brings the Nintendo Switch release you bought, expansion included, to iPhone, iPad and Mac in full: the original game code runs natively, every control is rebuilt for touch, the frame rate holds at 60 fps, and you are in a game one second after the main menu. There is now a native macOS version as well (first version): on an Apple silicon Mac it starts on double-click and works with keyboard, mouse and gamepad. Apple TV 4K (3rd generation, A15) has a community port (developer preview) that has reached the character-selection screen only on its author's device; see the device table below.

This is not a tech demo that "sort of runs". It is a mobile version polished for daily play, from your first character all the way through the endgame.

Platforms: iPhone / iPad (iOS 26 and later; iOS 18 – 25 with the older-API build) · Mac (Apple silicon, macOS 26 or later; macOS 15 – 25 with the older-API build) · Apple TV 4K (3rd generation, A15; community port, developer preview) · Game version: Switch release with Reign of the Warlock, 1.0.34.0 (corresponds to PC version 3.3.94012) · English / 中文 · License: MIT · Bring your own game files

中文: README.zh-CN.md

Build it with one sentence

Have your game files ready, then tell Claude Code or Codex:

Use the d2r-mobile skill from https://github.com/d2r-mobile/d2r-mobile to build D2R Mobile for my iPhone. My game files are in <path>.

The agent checks your machine, prepares the workspace, signs and installs the app, and copies the game resources to your phone. It stops to ask you for your Apple signing details and before any install that needs sudo. The skill lives at skills/d2r-mobile/SKILL.md, and both agents find it on their own through .claude/skills/ and .agents/skills/. The manual steps are under Getting started.

Why it plays like a native game

• Your phone runs the original program. iPhone and Switch use the same family of ARM processors. The rewriter changes only the instructions Apple's kernel rejects (thread-pointer registers, system calls, timers) and leaves every other byte as shipped. Classes, Runewords, Terror Zones, bosses, drop rules and quests match the original because they are the original code.
• Graphics go straight to Metal. A small host written for Apple platforms provides the system calls, files, audio and input the game expects, and reimplements its graphics API on Metal. The build translates every shader offline, so you never wait on a shader compile when you enter a new area.
• Older chips get their own textures. A16 and earlier chips lack the game's compressed texture format. The build adds a supplementary texture pack for them, and those phones hold 60 fps too.

What ships, and what you bring

The repository ships the rewriter, the host, the graphics layer, the iOS app, the test tooling and the full build pipeline. It ships no game program, art, text, data tables or shaders: your own machine generates all of that from your own files (see docs/GAME_FILES.md). The interface details we recorded to make the port work, such as shader interface descriptions, the graphics API function table and addresses inside the program, are listed item by item in docs/DERIVED.md.

The game runs fully offline and needs no online account. Multiplayer is out of scope.

Battle-tested

All 44 iPhones and iPads in the closed beta cleared Normal, Nightmare and Hell with several characters: 35 registered devices (25 iPhones and 10 iPads) plus 9 TestFlight accounts with one device each. The oldest, an iPhone 14 Pro Max with 6 GB of memory, holds 60 fps.

One install package covers iPhone and iPad.

Speed and battery

Measured on an iPhone 17 Pro Max:

Measurement conditions: whole-device power measured on 2026-10-10 on an iPhone 17 Pro Max, standing in the Act I camp at 50% brightness, with 60 fps and power saver mode measured in the same scene. Battery life comes from the measured power and the battery capacity, not from playing a full charge down to empty. Launch and game-entry times were measured on the same model in 2026-10; frame rate and act-change readings were taken on the same model on 2026-10-12 while moving through areas and changing acts.

The install package is a little over 100 MB. The game resources (about 5.6 GB) go onto the phone separately, and app updates leave your saves and resources alone.

Why it is this fast: the program executes natively, and not a single instruction goes through emulation; graphics go straight to Metal; every shader is translated offline and compiled ahead of time, so nothing is compiled when you enter a new scene. Older chips (A16 and earlier, such as the iPhone 14 family and iPhone 15) do not support the game's original compressed texture format; they need an extra texture pack made from your own game files, and then run at full frame rate too — see docs/LEGACY_DEVICES.md.

We rebuilt every panel and every action for touch, with one rule: keep the original interface language, and use gestures in place of extra buttons. Text and tap targets are sized for fingers. You can play the moment you pick it up, and long sessions stay comfortable.

• Move: a virtual stick with precise diagonals. Tap an NPC or the ground to walk there. Doors, portals and cave entrances respond to a tap anywhere on their surface.
• Fight: press a skill button to cast, hold to keep casting, and drag to aim at any angle; nearby monsters get targeted for you. You get two skill sets. Skills on your secondary weapons cast with one tap: the game swaps weapons, casts and swaps back, and the button shows the charges left.
• Boss health bar: pinned to the top of the screen with the percentage remaining.
• Items: tap, double-tap, long-press and drag and drop all follow your finger. Double-tap gear to equip or unequip it. Drag an item anywhere onto the vendor panel to sell it. On a stack, double-tap takes 1 and long-press takes 3. Long-press an empty inventory slot to sort everything.
• Text: you type with the system keyboard. Character names can be in Chinese; leave the name blank for a random one.
• Screen: on iPhone the game fills the 19.5:9 display edge to edge, clear of the notch and rounded corners. On iPad it fills the whole screen, and the interface centers itself when you open a panel. You can brighten the 3D picture.

Controller

Connect a controller and press any button: the interface switches to the original controller layout, with button prompts at the bottom of every panel. Touch the screen and the touch interface comes back. Inventory, stash, skill tree, Chronicle and settings all work with a controller, using the Switch button mapping.