The Justice System's new Legerdemain skill line contains five different passive skills, all with four ranks each. The very first passive skill is Improved Hiding which reduces the Stamina cost of sneaking by 10%. I reached Legerdemain skill level 6 which unlocked the second rank of this passive skill and it reduces the cost of sneaking by 20%. It's not much of a leap to believe the third and fourth ranks of this skill reduce the cost of sneaking by 30% and 40%, respectively.

The third rank unlocks at Legerdemain skill level 11, which is possibly two days away for me depending on how much the other passives help progress the overall skill line. Someone dedicated to the task could reach Legerdemain skill level 16 in a day's time in order to unlock that fourth rank. It will be a grind, though, due to the brakes ZOS has put in place to slow down leveling of this skill.

For those who spend a considerable amount of time sneaking in Cyrodiil, it might be worth the time to venture into PVE land and rank up this skill line. The other passive skills are not of any value in Cyrodiil unless you want to force open the locked treasure chests scattered across the land.