I asked if there were a way to neutralize this behavior, as the F3 button is sufficient for me, and is not accidentally pressable while I’m jamming on the punch button in Double Dragon.
Is there a way to simply remove this function? This is happening a lot, my thumbs are really big.
Can you just remap R3 to anything?
I have R3 set as my Next Shader hotkey for all cores except Desmume and Mednafen PSX (I use overrides to nul that button hotkey in those and map it to the actual R3), so I’ve never run into that issue in MAME. To just disable that button, you would first turn off autoconfig enable in Input settings. Then close RetroArch and open retroarch.cfg in a text editor and look for input_player1_r3_btn = “” and put a nul between the quotes.
To disable that button for only the MAME core, you can turn on load overrides automatically and configuration per-core off in Configuration settings. Autoconfig enable still has to be off or it will override any input settings you set manually. Then create a MAME folder in your config folder, then a MAME.cfg text file in that folder, open it and add the input_player1_r3_btn = “nul” line to that and save it. If you don’t already have a config folder, you can create it in your RetroArch folder and set it in Directory settings.
I’m not 100% sure if the latest MAME core needs the config folder and file named MAME or MAME 0.170. I use an older version that uses MAME 2015 as the name. You should get some yellow text informing you the override has loaded when you load a game if it’s finding it.
Ok, thank you Awakened, I’ll try that.
EDIT: I tried it, there’s already a “nul” between the quotes in the retroarch.cfg file. I guess I’ll try the MAME-specific solution you suggested then?
EDIT 2: Wait, turn off configuration per-core? Won’t that neutralize any core-specific input remappings I’ve made? I can’t have that.
Input remaps are separate from per-core configurations and overrides, so it shouldn’t effect those. They have their own on off setting and don’t conflict with the other settings.
If you are already using per-core configs instead of overrides you can also add or modify the input_player1_r3_btn = “nul” line to your mame_libretro.dll.cfg file.
Look I’m sorry but it’s already there, and it’s still resetting the game every time.
…They’re all tagged “nul.” What’s the deal here? This is confusing as all get out.
Autoconfig enable is off in input settings, right? When that’s off you need to go into your user input binds and bind everything manually. If you don’t use Bind All you could just skip over R3 to leave it unbound.
I tried binding it to a keyboard key, but it still caused the game to reset when pressed. I’ll try simply not binding it to anything as well, but frankly I’m not expecting much, it seems like RetroArch is dead-set on R3 being the MAME reset button.
UPDATE: Yes, Virginia, there is a Santa Claus.
Not mapping R3 did the trick. Thanks dude, you’ve been most helpful! 
ONE LAST UPDATE: Then I accidentally hit the L3 button too. 
So now I’ve unmapped them both.
It helps that I’ve never played a game where striking the thumb buttons under the analog sticks was necessary.
Sweet, glad that sorted it for you
I know this is an old post, but if you need help with this, here is what i did
use mame2016 core. hit tab on your keyboard to bring up the game menu, select other controls and find all service buttons. click delete on your keyboard for all service buttons to remove them. this way hitting L3 on your joystick will not activate the service screen. it seems to work for all games using retroarch, mame2016 core