I've been playing various Netplay games with my brother who lives in another state, and whenever we play a 4-player game like TMNT or Simpsons arcade, we almost always get some random "Anonymous" person who joins and plays for a bit. I know you can have password protected games on Netplay but I'm not sure how to set that up.

After much looking around i found an answer. The answer is below and the reason i was having so much trouble is because my version of retroarch didn't have the options in the menu. RetroArch.cfg has configuration for netplay "Request Device #" where # is any number from 1 to 16. Depending on your version of retroarch (since i've seen both) the "Request Device #" will be in the retroarch menu or you might have to go to the retroarch.cfg file and edit it manually, If your version of retroarch has the menu options available they can be found under Settings ==> Network -or- Netplay ==> Network. In there you will find "Request Device #" (# = number 1 to 16) set the controls / players you wish to control in the game. The client and host have to do this. Example: Host wishes to be players 1 and 3 Settings => Network => Request Device 1 = on (true if manually editing retroarch.cfg) Settings => Network => Request Device 3 = on (true if manually editing retroarch.cfg) Settings => Inputs => Port 1 Binds => Device Index = your controller (mine is labeled "wireless controller #1") Settings => Inputs => Port 2 Binds => Device Index = your controller (mine is labeled "wireless controller #2") Client wishes to be players 2 and 4 Settings => Network => Request Device 2 = on (true if manually editing retroarch.cfg) Settings => Network => Request Device 4 = on (true if manually editing retroarch.cfg) Settings => Inputs => Port 1 Binds => Device Index = your controller (mine is labeled "wireless controller #1") Settings => Inputs => Port 2 Binds => Device Index = your controller (mine is labeled "wireless controller #2") Retroarch will pair the first retropad (defined by Settings => Inputs => Port 1 Binds) with the lowest numbered Request Device and fill up. FYI if playing on the SNES ensure that Mutlitap is set for device type to enable the emulator to recognize players 3 and 4 (i set it in both places but you might only need it in one place) RetroArchGuy(Main Menu i guess) ==>Quick Menu ==> Controls ==> Port 2 Conrols ==> Device Type: MultiTap 2Gears(options i guess) ==> Input ==> Port 2 Binds ==> Device Type: MultiTap

I made some test today, and I confirm what @xwons said. I was running Retropie on a Pi4 and Retroarch on my laptop (same Retroarch version, same core, same rom). I did not perform any rom scan on neither system (see below), I was just launching the same rom on the same emulator. On the host side I went in Retroarch menu Netplay->Host->Start Netplay Host. On the guest side I went in Retroarch menu Netplay->Refresh Room List and selected the host room. Retropie is able to serve as a netplay host, that is, I was able to join the Retropie netplay host room as a guest from Retroarch running on the laptop. Retropie cannot join netplay as a guest, that is, when I try to join the host room of Retroarch running on the laptop, I get the message "Failed to locate matching content by either CRC or filename". This also happen on any netplay host room I see in the room list, despite running the same core and the same rom (same CRC) I also tried installing Retropie on an Ubuntu virtual machine, obtaining the same results. I add that also I tried to create a playlist by scanning the rom directory, by going in Retroarch menu Main Menu->Load Content->Playlist->Scan Directory, selecting the rom directory and then Scan This Directory. On Retroarch running on the laptop this correctly created a playlist with the roms found in the directory, while Retropie is not able to find any content.

@mitu Thank you. That's all I needed to know.

@Daistaar said in Netplay questions: Can two Pi's connect directly via LAN?: Would this allow, say full screen multi-player Mario Kart for each monitor? Would they still just see everything split? That would require heavy hacking on the game roms themselves, while RetroArch's Netplay just uses the unmodified roms and spans the players' monitor & controller cables through the network, figuratively speaking.

@Efriim said in Error when starting netplay host: @saccublenda Perhaps there is the same setting somewhere within retroarch. Indeed there is. Under Settings -> User -> Username (it sets the "netplay_nickname" in retroarch.cfg). With this matching the hostname I can start the netplay host from retroarch menu. It is a peculiar thing, I remember it working without configuration, I had a hostname so I don't really understand it. Same here. I used to have a netplay nickname different from the hostname, and it didn't matter. Weird.

@mitu said in Can't seem to get Netplay to work: @mikespie Please add more info about your system - https://retropie.org.uk/forum/topic/3/read-this-first. The core means which emulator are you using for the running the game. You need to use the exact version of it and also the exact ROM on both systems. Since you're running a Megadrive rom, the core should be either lr-picodrive (I think this is the default) or lr-genesis-plus-gx (see the Megadrive docs). Thank you for your response, sorry for not providing all info. Just from your post I was able to figure it out and have Netplay working / connecting now! However, it seems as though the controllers do not work in a lot of the games while on Netplay. I have tried using different emulators to no avail. An example is Street Fighter II for Genesis, Player 1 controller works fine, but player 2 controller doesn't work at all. Tried a keyboard as well, both which work fine not in Netplay. My system is a CanaKit - https://amzn.to/2Taj5jf PI 3 B+ w/ 2.5A power supply RetroPie V 4.4.4 (skyscraper-pr6-v3) Built from premade SD image on RetroPie website I have a USB keyboard, mouse and controller hooked up to it Controller is working great outside of Netplay, it's an "EasySMX 2.4G Wireless Controller" and also a Geeekpi SNES USB controller Emulator is lr-genesis-plus-gx Thanks again!

shot out of left field here, but did you ever end up figuring this out? same issue and the web is completely barren of references to the issue apart from yours lol

@madmodder123 Cheers. Have you used Netplay outside of a LAN type situation? I've heard it's optimized for LAN use and doesn't work well over the interwebs.

@revlied Please do not post a support request without first reading and following the advice in https://retropie.org.uk/forum/topic/3/read-this-first Along with the information requested there, what part of the Netplay documentation seems outdated?

I run it directly via scripts: (Host Coop) #!/bin/bash /opt/retropie/ports/zdoom/zdoom +set fullscreen 1 -host 2 -warp 01 -skill 2 -iwad /home/pi/RetroPie/roms/ports/doom/doom2.wad -file /home/pi/RetroPie/roms/ports/doom/mod.pk3 or (Host Deathmatch) #!/bin/bash /opt/retropie/ports/zdoom/zdoom +set fullscreen 1 -host 2 -deathmatch...... or (join) #!/bin/bash /opt/retropie/ports/zdoom/zdoom +set fullscreen 1 -iwad /home/pi/RetroPie/roms/ports/doom/doom2.wad -file /home/pi/RetroPie/roms/ports/doom/mod.pk3 -join 192.168.X.X OR Check out the Retropie Doom wiki, regarding mods. You could use the same commands above, but put it in /opt/retropie/configs/port/modname/emulators.cfg (that's what the "runcommand .sh " 0 Port" doom" stuff is pointing to...the "doom" directory in /opt/.../configs) Edit: (Here are some images I made to dress up the MP scripts) https://imgur.com/a/C6GCc Reference: https://zdoom.org/wiki/multiplayer

So the conclusion then, is that Netplay through lobbies really doesn't work or is not a supported feature in RetroPie, @mediamogul?

I'm experiencing exactly the same problem. I hope someone has a solution.

@flxfit well we dont close threads since they help more than the original poster. But please share with us how it worked as so to benefit others.

I added a few options and some AI bots. @BuZz Any update about the binaries ?

Sorry for resurrecting this thread. Are there any news on the integration of this feature in Retropie? I wrote a post asking for directions here. It seems that I can host games just fine, but I am unable to join games from the room list, as I always get that "Failed to locate matching content by either CRC or filename." I downloaded the databases and scanned the content, but it seems that retroarch is still unable to find any cores and games from my collection. PS: I tried following the instructions by @mediamogul , but the scripts /opt/retropie/configs/all/runcommand-onstart.sh and /opt/retropie/configs/all/runcommand-onendsh are not there anymore in the last version... Any ideas?