Gamepads are more comfortable than KBM.
Okay, this will sound either like beyond-obvious to some or total heresy to others (side I used to be on)...but it`s something I been deliberating on a lot recently. So, was quite happy to see this thread appearing. Of course some gaming genres will always be better off on a KBM, and while roguelikes might initially look like one of these, my recent experiences convinced me otherwise.
You see, I`ve been playing RLs on my handhelds a lot - NDS & PSP. There`s not much choice, but you can find a few ports, and they all utilize the DPAD/buttons/shoulders - to a better or worse effect. Of these:
Powder (NDS) - uses the "standard" system similar to the one Jo describes above. Movement on DPAD, buttons/shoulders easily configurable and START takes you to a command list. Works great - but this game was coded as a handheld (GBA) native, so it`s bit different from the PC-centric majority.
TOME/Angband (PSP) - these are PC ports and the conversion wasn`t complete - or maybe not conversion itself but the UI implementation. Main method for commands: pressing (and holding) Triangle brings up a a tiny letter set which you then navigate with DPAD. Quite a chore, especially trying to get to capitals/symbols - you have to hold shoulder button simultaneously. Everytime you need "*" for example, so common in lists - it`s really tiresome. Theres also another shortcut, holding a button + DPAD navigates some pre-set commands, not too bad though a bit messy and you need to dig into config to set these up.
Nethack (PSP/NDS) - this is similar to Powder with rather "normal" DPAD movement, configurable buttons and main command list called with a button. Again, plays great. (Though diagonals dont work from DPAD fro some reason - you need to use touchscreen. Strange, but probably just coding omission)
So, the Powder/Nethack method already proves it`s very much doable - and most importantly, playable. I`d already pick it over KBM (in some circumstances at least, like my current uncomfortable desk). But that`s not all - saved the best for the last...
Crawl (NDS) - a revelation, no less. This is a port of Linley`s DC 4.0 beta - and it absolutely rocks. Putting aside the awesomeness of the game itself, the control scheme here is a strike of genius. At first it totally bamboozled me and I put it aside as a curio, fired it up one day after Powder overdose, got into it and never looked back.
First, major change: pressing a DPAD direction won`t move you anywhere. You have to press A (while holding the direction) for that to happen. Sounds insane? Thought as much too. And yet...give it a whirl and it soon becomes a second nature. One thing, diagonal "problem" disappears. The other: it`s a lifesaver for a hotheaded players like me who kind of rush everywhere by just holding a direction, which is quite often suicidal. So, a safety lock of sorts.
Second: all the major commands are mapped to the DPAD too. Sounds even crazier? Yep... but it works incredibly well. This system lets you map 9*4 (buttons ABCD) keypresses. Minus the 8 needed for movement and you have 28 bindable combinations - should be sufficient even for RLs with big command sets. There`s a visual hint when you hold a direction - it highlights ABCD options on-screen, so you don`t have to memorize them.
The main advantage of this system is perfect streamlining. Mostly I just use DPAD+ABCD, occasionally two others for map and "big" inventory. No need to dive into menus or fiddle with multiple buttons. Heartily recommended, would be more than happy seeing this implemented for old and upcoming roguelikes. I know it sounds convoluted on paper, but is a breeze to learn and use, really - and worth seeing in action, if you don`t have an NDS I suppose it could be emulated too.
And yeah, the diagonal-modifier method has been used in jRLs like Mystery Dungeon or Izuna and it works great.