Stealth is generally based on Agility.


Which JA are you talking about? 1, 2, or 3?


For 1 and 2, there's almost always a noise factor. Characters better at sneaking will make less noise. That's also true of the enemy. You can sometimes "hear" where the enemy is, even without visual sight . As far a I can tell, 3 doesn't model sneaking noise, and I'm certain it doesn't model visual cones. It just detects proximity to the enemy before starting an alert timer (Keep in mind that this is just my impressions from playing 3; I haven't sought out any mechanics info yet).

Agility is the most necessary stat, because you need the AP to actually get to the enemy. Of course, you need AP for everything in combat, but in melee it's especially important because you can't win if you can't even damage the enemy. Strength is also used to determine damage, but I put that stat a distant second to agility. In 3, the perk system has pretty crazy movement-based perks if you have at least 80 agility, that leads to melee-based characters being absurdly powerful (stealth or not)

For 1 and 2, *Shooting* at point blank will alert guards through noise. A silencer can help with that, but doesn't eliminate all the noise. *Knifing* someone won't make noise so nearby guards won't get alerted A merc can sneak up from behind an enemy group and continue to knife enemy after enemy until one happens to turn around, or there's a miss and the guard alerts the sector.