By default (atleast on my PC version) there are 3 different keys for shooting: L-Shift, Spacebar, R-Shift By using multiple keys and mashing them repeatedly (like playing a rhytm game :) ) one can achieve way better damage output on many weapons.

I couldn't find any ruling disallowing this usage, but I did notice while watching the current world record: https://www.speedrun.com/downwell/run/y9117xrm FlabCaptain opted to not use this technique. What are your thoughts on allowing this? I personally think there is nothing wrong with it as it is just part of the game.

I also want to clarify, that I'm not talking about any OS/Hardware -level keyboard remapping, just about using multiple of the default keybindings.

I have no idea how I never noticed this.

As you said, it's completely possible in game, so I see no reason not to allow it! I'm curious as to what changes this would make to the run. Faster boss fights, obviously, but it could also help with stubborn enemies in reservoir/abyss. Are there any weapons in particular that benefit from the extra speed?

Using this technique, you can get higher DPS with weapons that seem to have a skippable shot delay (Machine Gun, Triple, Noppy, Burst and especially Puncher). You also get a slight benefit with Laser and Shotgun, since although you need to wait for their delay before firing again, more presses as the delay ends means a potentially-earlier next shot.

Also, using this technique when your gunboots are empty actually gives you a decent 'brake' (since shooting while empty reduces your fall speed just a bit). Not sure how useful this would be for the run, but just something I noticed.

Since it's in the game, I also feel it's probably fine. Though as a controller player, it makes me wonder, should mapping multiple buttons to shoot also be allowed, for parity? (I think I just have one button for shooting—I don't know if that's something inherent to the game or just the default mapping Steam gave me.)

Hrm. Controllers only have a single shoot button. I play on controller as well, which is probably why it took so long for this trick to get brought up.

About mapping multiple buttons - this is a difficult issue I'd like some suggestions on, since this is my first time modding a game.

On one hand, it's true that keyboard has an inherent advantage due to having multiple fire buttons. But conversely, letting players bind multiple shot buttons risks an arms race where people just try to hit as many buttons as possible - or even take the Doom Eternal route and just map shot to a mouse wheel. It would, in essence, turn into a turbo button, which obviously wouldn't fly.

Also worth considering is that the game is multiplatform. Non-PC platforms presumably can't do the same thing to give themselves extra key bindings, so letting PC players do it is an inherently unfair advantage.

Of course you could limit people to three fire buttons maximum, but this would be nearly impossible to moderate. You'd have to ask players to show their inputs on the entire stream, which seems like overkill that just makes things really inconvenient for non-PC players.

I think the dealbreaker for me right now is that the extra shoot buttons on the keyboard are awkwardly placed. If they were right next to each other then I'd be more inclined to let custom keybinds do something similar, but on a quick test I found that this is just a really uncomfortable way to play the game. (I was using A/D to move and Space/Right Shift to fire, and the awkward hand positioning really messed up my fine control.)

In any case, my current leaning on this is not to allow external keybinds for extra fire shots. But if I've missed something here please let me know and I'll take it into consideration.

I think that is reasonable in principle. Thinking further, enforcement—not just regarding mapping multiple buttons, but in general—might be another can of worms... Consider these different ways, of varying legality, to shoot quickly:

-using multiple default shooting keys (left shift, space, right shift) -using multiple remapped shooting keys (e.g. j, k, l) -very fast mashing or piano-ing two or more fingers on one shooting key or button -mapping multiple shooting buttons -using a controller and keyboard simultaneously -a non-blatant turbo macro -miscellaneous goofy setups (mouse wheel mapped to shoot, foot pedals, etc.)

I don't think I could distinguish between these in a recorded run, even with inputs displayed.