MDProMod — Play a full Yu-Gi-Oh! duel inside Minecraft

Place a Duel Field, load a Card Case, press the green button: the opening deal plays, the phase buttons light up one by one, and your opponent is one of 57 WindBot AIs. This isn't a card skin — it's a complete duel running on the real ocgcore rules engine.

What a duel looks like

• The Duel Field is a large in-world structure: 16×14 blocks with 32 zones laid out like a real play mat — Monster Zones, Spell & Trap Zones, Field Spell Zone and Extra Monster Zones.
• Put your Card Case on your half and an AI Deck on the far half. With both sides set, the green button on your side turns Ready.
• The opening hands are dealt with an animation, then the six real phase buttons appear: Draw, Standby, Main 1, Battle, Main 2, End. Which phases you may enter is decided by the engine — trying to skip ahead is simply refused.
• Everything is decided in the world, not in menus:
  • Left-click your cards (hand or field) for an action menu — Summon, Special Summon, Set, Activate, Attack, Change Position — showing only what the engine actually allows.
  • When a card needs a location, the legal squares glow green; look at one and left-click.
  • Card selection, chain, sorting, material, option and confirmation prompts open as Minecraft-styled windows with card-art grids and tooltips showing each card's name and where it is.
• Live LP: damage, recovery, costs and set-to-value are all tracked, and the LP screen under the field keeps score.
• Gold Victory and grey Defeat states — right-click to go back to Ready and duel again.

Everything from Master Duel, ported over

• Six summon sequences (Fusion, Synchro, Xyz, Link, Ritual, Pendulum): materials drawn in → a magic circle unfolds at the centre of the field → the monster lands, using Master Duel's own 3D meshes and measured timings (Fusion 3.3 s, Link 6.8 s, …).
• 497 ace-monster cut-ins, played back as real Spine skeletal animations — scaled to the field, facing every player's camera, visible to everyone nearby.
• 11,091 monster closeups floating above the field (popping in after 0.3 s, breathing for 5 s, tinted by attribute).
• 110 BGM tracks and 2,443 sound effects. Pick one track each for duel / ace summon / low-LP climax with the Music Settings item; summons, attacks, phase changes and menu clicks follow Master Duel's own cue timings.

Card data

• 15,019 cards built in, with the ocgcore rules and card text — fully offline.
• 57 WindBot decks with names and personalities: Blue-Eyes, Branded, Tearlaments, Swordsoul and more.
• The deck editor lives inside the Card Case: search, filter, build from the entire card pool, with deck-size and banlist checks, plus .ydk import and export.

Survival mode

Requirements

• Minecraft 1.20.1 with Forge 47.4.20 (any 47.x works)
• Windows x64 — the bundled duel host is a Windows program with its own .NET runtime. macOS and Linux are not supported yet.
• Install on both client and server (singleplayer counts — the duel runs on the server side).
• About 1 GB of disk (566 MB mod jar + 396 MB unpacked). 4 GB+ of RAM recommended.
• No external install required — no MDPro3, no ygopro, nothing else.

First launch unpacks itself (this is normal)

On the first launch the mod extracts card art, closeups, summon effects and the duel host out of the jar into <game dir>/mdpromod/: roughly 26,500 files / 396 MB / ~35 seconds. A progress readout scrolls on the action bar, and a "resources ready" note appears in chat afterwards. Later launches only compare snapshots (~2 seconds). You can delete that folder at any time — it is rebuilt from the jar.

How to start a duel (30 seconds)

1. Right-click the ground with the Duel Field — the field appears.
2. Right-click with the Card Case — the deck editor opens (craft one first in survival).
3. Sneak-right-click to place the Card Case on your half; place the AI Deck on the opposite half.
4. Press the green button on your side → Ready → Start.
5. Left-click your own cards to see what they can do; watch for green squares when you need to place something.

Commands (optional — for testing and screenshots)

FAQ

Can I duel a friend? This build is player vs. the built-in AI — the far half must hold an AI Deck for a duel to start. Human-vs-human is not implemented yet. On a shared server, players nearby can watch your animations and hear your duel, but only one duel runs at a time.

Why does the first launch take half a minute? Because every asset ships inside the jar — that is exactly why nothing else needs installing. It happens once. (Delete the folder if you want to watch it happen again.)

Why do some monsters have no closeup? Closeups exist only for the 11,091 monsters Master Duel made them for. Missing ones are skipped silently and do not affect the duel.

Can I turn effects off to save performance? Yes, with launch flags: -Dmdpromod.closeup=false (closeups), -Dmdpromod.cutin=false (ace cut-ins), -Dmdpromod.summonFx=false (summon sequences), -Dmdpromod.duelAudio=false (duel sound effects), -Dmdpromod.duelBgm=false (background music).

Why Windows only? The bundled duel host (ocgcore + .NET) is currently published for Windows x64 only.

Where do the cards and art come from? Rules and card data come from ygopro's ocgcore and card database; art and audio come from Yu-Gi-Oh! Master Duel and community art packs. This is a fan project for study and personal use — please support the official release.

Known limitations (0.1.0)

• AI opponents only; no human-vs-human duels yet.
• A few decision windows are still chat-only (sorting chains, counters, tribute/material counts, declarations) — they print the engine function in chat when they come up.
• Hidden-information filtering for multiplayer is still being finished.
• Windows x64 only.
• The Duel Anchor block is currently decorative.

Credits & license

• Rules and card data: ygopro / ocgcore and MDPro3 (GPL-3.0) — this mod would not exist without them.
• Art and audio: Konami's Yu-Gi-Oh! Master Duel and MyCard community art packs (for study and personal use; please support the official release).
• Bundled runtimes: Spine Runtimes (Esoteric Software) and libGDX (Apache-2.0).
• This mod is released under GPL-3.0-or-later. Source: https://github.com/hailam0314-cell/MDProMod.

Based on MDPro3 — derivative work notice

MDProMod is a derivative work built on top of open-source Yu-Gi-Oh! projects, and redistributes parts of them:

• MDPro3 — https://code.moenext.com/sherry_chaos/MDPro3 (mirrored on GitHub) — GPL-3.0. This is the project MDProMod derives from: our bundled duel host binaries (ocgcore, ygoserver, Lua card scripts) and the asset-extraction pipelines come from its release build.
• ygopro / ocgcore — the open-source rules engine the duels run on. Its Lua card scripts are GPL-2.0 (licence file travels inside script.zip).
• WindBot — the AI deck logic, taken from the MDPro3 build.

How MDProMod differs from MDPro3: MDProMod is not a re-upload or a repack — it is a Minecraft Forge mod that talks to the same rules engine through our own C# host (tools/duel_host/, a JSON protocol) and reimplements the entire presentation layer for Minecraft: the duel field as a 16×14 in-world structure with real phase and confirmation controls, in-world card action menus, location picking, Minecraft-styled prompt windows, chain/target markers, monster closeups, cut-in playback, per-moment BGM and survival crafting. The asset pipelines under tools/ re-encode Master Duel assets for Minecraft (1/8-scale cut-ins, 128 px closeups, OGG audio); how they are packaged, extracted and played back is original work. The mod id, commands, items, blocks and UI are all ours — nothing about MDPro3's Unity client is reused.

Full licence and third-party notices: https://github.com/hailam0314-cell/MDProMod/blob/main/THIRD-PARTY-NOTICES.md