Total Barrage is correct. As a thief player myself, I can assure you that as long as he’s landing his attack that gives him stealth, he can restealth just about every 3 seconds as long as there’s targets to hit and initiative to burn. Combine that with the heal that also stealths, and the potential for a stealth ability through stealing, not to mention utility skills, a thief can stealth VERY often in optimal situations.
The only drawback is the “Revealed” debuff, which lasts 3 seconds.
A thief can also stealth then do the execute animation, which doesn’t reveal the thief until it completes(counts as an attack). A thief also gets a special attack from stealth, based on their primary weapon.
With so little information, it’s hard to tell exactly what the OP saw. But this doesn’t sound like a hack or exploit, it’s sounds like a thief knowing his class and playing like a champ, and the OP not understanding how thieves work.
I don’t know about the inability to click on him, but that could have been lag. Try using tab to target enemies instead. Also, a thief being in stealth does NOT make him invulnerable. Use AOE attacks around the area you think he’s at. You can even swing melee weapons in their general direction. Again, as a thief player, let me assure you that I have been hit AND killed while in stealth by lucky guesses with these kinds of attacks.
