In my experience, I can't walk down the stairs in the orc mines without waking the whole room that very turn one in three times unless I'm invisible. This with a SpEn wearing a robe who's had stealth turned on all game long. All it takes is one enemy, who immediately shouts every time. I usually just run the hell away and come back at them with meph cloud.
Later on, the only thing my stealth nets me is single sleeping enemies.
- Code:
...#...........CC.
...#....C.........
...#....C........C
...@..............
.............C....
Trying to sneak up on that ^ without invis is likely to turn me into a pincushion. You might stab one or two, but using the shortest route, you're looking at 66 stealth checks to stab them all. 24 of those before you even reach the closest two. Compare to ~5 stealth checks to sneak up on one enemy. I don't know what the awareness is on a centaur, but it's going to be high enough (At least 26 or so) that getting less than a 1/20 chance of being found per check is really damned difficult. You'd need at least 'uncannily stealthy'. Unless you're invisible, in which case you might as well be a Troll in gold dragon mail. And even with that 1 in 20 chance per check, you got a 29% chance of reaching even the closest 2 guys before one of the 6 wakes up. This is for lowly Centaurs. And only 6 of them. With stealth higher than what I'd have on a SpEn with 20 Dex and 27 Stealth.
As far as adding variety, right now you might as well strip any +dex, +stealth, and the last 10 levels of the skill from the game. I'd like there to be some actual value to those things so I don't look at a randart ring with +6 dex ++Stealth +rF and say 'eh, the +rF +rC ring actually helps against cold at least. No point in switching'. Or look at my skills and figure that 20k xp is better spent on anything at all other than stealth, even as a spriggan. About the only decisions about my character to make after the lair are what spells to learn. Equipment is a no brainer in favour of spellcasting, resists and carry capacity, with stealth not even on the radar.
Also remember, this proposal really only affects
stabbing against groups. Stealth for the purposes of dropping a firestorm on their heads or summoning an army doesn't require more than the initial 1 turn to see them anyways. It hardly matters if you can run circles around those C's above without waking them up if you're a summoner anyways. And if you are a stabber, the current method is to confuse them or invis them, which isn't really any different than dropping the firestorm or summons on them. There's no concern for approaching from different angles or exploring around the other side to see how big the group is; you already know it's a completely lost cause to try stealthing anywhere near them. Every time. Actually making it viable to sneak up on groups means you'll want to scout around the edge of the group to see if there's a sensitive guy mixed in there or something wandering around. And they still have a chance of waking up, just like anything else, just not a 90% chance before you get in melee range. It's certainly more interesting than stabbing entire groups before they (never) break out of confusion, or before your invis (never) wears off.