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Netplay Guide (EN)

LionSquall edited this page Apr 27, 2019 · 8 revisions

I- Introduction :

The netplay is a retroarch feature that allows multiplayer networking with some emulators, and also has people who can join in viewer mode.


  • Use roms from No-Intro romsets for console games (dumps closer to original games and compatibility chart by available rom)
  • Connect your machine to RJ45 ethernet cable (a wifi connection is much less stable)
  • If you use a Raspberry Pi2, Pi3-b and Pi3-b + an overclock (at 1300 MHz) is advised to see mandatory.
  • For x86-64 (64bit), x86 (32bit) and Odroid versions the overclock is not necessary.
  • Have a box that manages the UPNP or open its port manually.

II- Preparation of Rom:

You must respect 5 steps so that your roms are prepared to play in Netplay.

A - Netplay Compatible Fullsets:

1. Arcades:

  • Fba_libretro> Romset fba_libretro

  • Mame According to (Choose the romset according to the core wanting to be play)

  • Mame2003> Romset mame (0.78) [Default Core]

  • Mame2003Plus> Romset mame2003plus

  • Mame2010> Romset mame (0.139)

  • imame4all> Romset mame (0.37b5)

  • Neo-geo> core fba libretro

2. Consoles:

  • Master-System (picodrive)
  • Megadrive (picodrive)
  • Nes
  • Snes (snes9x - enable multitap)
  • Pc-Engine
  • Sega 32x
  • Sg-1000
  • Supergrafx

B - Sort your romsets

The different preferences of sorting.

1 - National or international?

  • National: If you want to play only with people from the same country as you: keep only the roms of your country ** then privilege the roms USA and Japan for the missing ones. **

  • International : If you want to play with people from other countries: keep a rom of each country.

Put an example

2 - The Retroachievements:

Some retroachievement trophies, need rom USA to validate the retroachievements and certain games exist only in version JAP.

3 - Sort with software

To find out what the codes and tags in the roms are.

Several software exist either:

  • Universal Rom Cleaner

  • Clrmamepro (using a dat file)

  • Romulus (using a dat file)

  • RomCenter (using a dat file)

4 - Sort by hand

Tedious work that will require a huge patience and a lot of time.

C - Get a dat file for sorting software

Download the dat files of your consoles to sort.

D - Scraping your romsets

Several ways exist to scrap your roms:

1. Scraper with built-in Recalbox tool.

EmulationStation Menu> Scraper

2. Scrap your roms with dedicated software to keep more information in the title of your games (Metadata example: Hack Region translation)

  • Skraper (compatible windows / Linux and soon Mac).

  • Universal XML Scraper (windows compatible)

Skraper video tutorial and Universal XML Scraper:

E - Hasher your Rom

The HASH is a unique digital fingerprint for better recognition when choosing a party (this is a CRC32 checksum from the rom).

The Hash is therefore mandatory for the proper functioning of the Netplay.

Emulation Menu> Game Options / Netplay Options> HASH

However roms will not have Hash, this is the case of Arcade systems:

  • Fba Libretro
  • Mame
  • Neo-Geo

Note: Some programs can hasher and scrapper at the same time.

III- Setting the Netplay system

A- The Relay Server

If :

  • your router does not support the UPnP protocol (open and close ports automatically)
  • you can not open your ports
  • you have a doubt Enable the option Use the Netplay MITM option.

This routes both sides of the connection through an intermediary server. But it is recommended to open its port or have a box that manages the UPnP, because the relay server will add additional latency and dependency to the latter.

Warning !
RetroArch does not check if your ports are open, any more than the libretro lobby server. Make sure you do this correctly or enable the relay server, otherwise users will not be able to log in to your session.

B- Set up your port

1. Verify that your port supports UPnP:

2. The answer is "positive":

You can play without the use relay server option (your port opens automatically).

3. The answer is "negative":

Open a port manually (recommended) or use Netplay MITM.

Direct connection (relay server off) It is necessary to open the port 55435 of your internet modem, some modems have the UPnP which allows the automatic opening.

Open your port manually: Depending on your ISP the operation to do is different. Find out about your operator's website or forums.

Netplay MITM option Relay Server allows you to override the ports of your modem. However this will have an impact on the speed at which the data synchronize and thus on the responsiveness of the game

C- Configuring your nickname

We advise you to put the same nickname as on Discord in order to find your way more easily.

EmulationStation Menu> Game Options / Netplay Options> Nickname

Enter your username

IV- Netplay Notice

A- The Netplay lobby

You do not need to configure anything to connect to the netplay lobby. Go to the Netplay menu, select Lobby Netplay, and select the server you want to connect to.

To access it, press X (depending on the configuration of a Snes controller) and then Netplay Lobby.

For each game, you will have information:

  • Name: Player name of the host (the icon confirms that it is under recalbox)
  • Country: Country of your host's server
  • Hash of rom: Correspondence of the Signature of the rom
  • Rom file: Correspondence of the rom
  • Core: Emulator used
  • Ver. of the Core: Version of the Emulator
  • Latency: Ping
  • Ver. of RA: Version of Retroarch
  • Arch. of the Host: Host Architecture

You will see the result in the bottom of the window (and in front of each item of the list) indicating you the chances of success of connection:
Green: You have good rom with the good hash, the good core, all the chances are on your side for it to work!

Blue: No hash match (some roms do not have hashes, like arcade systems), but the correct file has been found. It should work !

Red: File not found, forbidden system, not good core: no chance that online gaming works! (nothing will be launched)

B- Host or Customer?

Host: "Start hosting" in netplay by selecting the game you want to network with the Netplay key and wait for players.

Customer: Join the netplay lobby and select the host you want to connect to.


1- Why can not I host?

There are 2 possibilities:

  • Insufficient internet connection
    Try as a customer.
  • Your port does not open automatically
    Try using the NETPLAY MITM function
    Open your port manually (Recommend)

2- If I start the hosting, the game is shut down and returns to the recalbox menu.

Check that your cores are in line with your machine (pc, raspberry pi or other). In addition, some machines only support the client function.

3- Does Netplay require port opening to work?

Yes, the host and the client must open the ports correctly.

There is a backup option that can be used by those who can not open their ports (NETPLAY MITM function).

4- What do you need for the netplay to work properly?

  • Same version of Recalbox
  • Same core for the emulator
  • Even rom (identical rom signature, named to the letter and punctuation near)
  • Be connected in RJ45

5- Does the PSX / N64 netbook / Dreamcast / GameCube / Wii / 3DS work?

No, the performance requirements of these consoles make it difficult to netplay.

6- Can I play GB / GBC / GBA / PSP / 3DS games with multiple people via Netplay?

No, the RetroArch netplay is not a link cable emulation.
GB, GBC, GBA and PSP are currently not possible with our implementation. Trading Pokémon and others are impossible.
But, a notable exception is the same GB / GBC Netplay game via the TGB-Dual and Sameboy cores.

7- What are Netplay compatible cores?

A. Arcades:

  • Fba_libretro (core fba_libretro
  • mame 2003 (core mame_078)
  • neogeo (core fba_libretro

B. Consoles:

  • Master-System (picodrive)
  • Megadrive (picodrive)
  • Nes
  • Pcengine
  • Sega32x
  • Sg1000
  • Supergrafx
  • Snes (snes9x - enable multitap)

8- Which are the cores Not compatible Netplay?

A. Consoles:

  • gb
  • gba
  • gbc
  • psx
  • n64
  • psp
  • prboom
  • nxengine
  • scummvm
  • dosbox
  • 3DS
  • atari7800
  • atarist
  • amstradCPC (Caprice)
  • vectrex
  • game and Watch
  • odyssey
  • ZSpectrum

B. Standalone emulators:

reicast, N64 MupenPlus, Amiga.

Recalbox Netplay video tutorial (Fr):

















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