If all classes can stealth ...i think Nightblade should be able maybe to gain invisibility for very long period of times or even permanent ? I didnt play Skyrim and i dont know how stealth will be in ESO ..it will be partial invisibility ,like if you move near a player ,eventually he will spot you easy, or it will be like in all mmos out there completely invisible ?!

I think only nightblade class should have a strong and perma stealth , because if other classes can stealth for example like 5-7 sec and nighblade can stealth 15 sec ..that will not be of a good advantage ,and it will like stealth is just a gimmick and not a big advantage for this class.

I for example , i play the stealth class for good perma stealth, if there will be just a small time differences betwin classes ,i wont play the stealth class because it is not a real stealth class. For the fragile light armor user + 10 sec of stealth vs a heavy armored tank wont make a much difference in pvp or in 1v1

Everyone can stealth and do sneak attacks, nightblades get a temporary invisible skill and some other bonuses such as attacks usable from stealth.

Nightblades are the only class to gain the invisibility spell and Assassin-like abilities.

Stealth works by light sources and distance. If you are in a very dark area and not near anyone, you might as well be invisible but the closer someone is to you and the lighter the area, the more likely you are to be detected. Being in stealth also drains you stamina as well, so no class can be in perma-stealth.

I guess you could say it is somewhat similar to DDO's (or even D&D tabletop) stealth mechanics.

So it is not a real invisibility like in rift ,wow ..etc ,it 's more like a kind of hide element ,only good in dark places and maybe walking slow. That may change my view about what class il chose or even if i play the game , I was think nightblades can more than open with an attack from stealth (that all classes have ) :/

No it's not permanent but still a viable class

As i just said, nightblades get true invisibility as a spell for a short time.

Go play skyrim and you will know basically what stealth is like in ESO.

I'm reasonably sure that you only drain stamina while moving. So if you are motionless you can be "invisible" indefinitely. The catch, of course, is that you CAN'T remain motionless forever; foes (or, even more likely, other players) may move near you and if they get too close they will spot you, so you have to move to stay out of line of sight / behind, etc and when you move, there goes the stamina drain... should be fun, I think.

Better than just "boom, I'm totally invisible forever" like many games have, but also better than games that give you like three seconds of stealth and then BOOM you're out of stealth and have to wait some time before you can go into stealth again. Should be fun judging the patrol routes of NPCs, making sure you have a spot to hide in along the path you plan to take, etc.

Of course ANY class can do that; the Nightblade does get some more specific stealth-tailored abilities.