Dimension Dodger

Rogues often pride themselves on their ability to hide from view, losing themselves in crowds or shadows. A select few, touched by the planes, take this obscurity to new lengths; they opt to use the innate planar magic of their surroundings to transfer in and out of the Material Plane - concealing themselves behind the fabric of the multiverse itself. As they use universal boundaries in their craft, such rogues often travel to many planes, searching for targets, treasures, or simply experiences. Slipping in and out of reality makes them expert thieves, elusive spies, and adroit adventurers.

Worldtear

When you choose this archetype, you gain some knowledge of worldfringes: extradimensional spaces between planes of existence, yet not defined enough to be demiplanes.

As an action on your turn, you can open a small tear in your current plane and move into a worldfringe for about 12 seconds, or until the end of your next turn. Fringes appear as an endless black space, whose air feels dense and heavy like water, but remains breathable. While within a fringe, you can see creatures, structures, and land of the plane you just left within 30 feet of you, represented as blurry, indistinguishable glowing figures. You can perceive the general form of things beyond this distance, but they appear substantially more blurry and difficult to focus on.

You can't interact with creatures, objects, or surfaces upon the plane you left - you simply pass through them, allowing you to move through otherwise solid surfaces. While you are within a fringe, creatures on that plane can't see or hear you, and spells, effects, and attacks from that plane can't target or affect you. You can move freely within a fringe on your turn, though the thick atmosphere causes it to be difficult terrain. You can exit a fringe prematurely as a bonus action. When you would emerge from a fringe within an occupied space, you instead simply emerge in the nearest unoccupied space.

Planar Slip

Also at 3rd level, you begin to find weaknesses and even errors in the structure of the multiverse.

You can use a bonus action to create two immovable rifts, one on an open surface within your space and one on an open surface that you can see within 30 feet of you. An unstable portal bridges the distance between the two.

The rifts are no more than a foot across and last until the end of your turn. A creature next to one rift is considered to be next to the other rift. Anything put through one rift emerges through the other. You may only have one Planar Slip open at a time.

If you are within a Worldfringe when you use this feature, only the rift in your space opens, bridging your location and its corresponding position in the plane you left from.

You have advantage on Sleight of Hand checks performed through a Planar Slip.

Slip Sneak

At 9th level, you master using your portal legerdemain to catch foes unaware.

You can use your Sneak Attack against a creature within 5 feet of your Planar Slip even if you don't have advantage on the attack roll, but not if you have disadvantage.

When you make a Sneak Attack this way and you have advantage on the attack, you can remand the creature when it is within 5 feet of the Slip, forcing it into a Worldfringe if it is Large or smaller and both attack rolls would hit it. It stays remanded until the end of its next turn, and is also incapacitated while remanded; once you remand a creature this way, you can't remand it again for 24 hours.

Linewalker

At 13th level, when you create a Planar Slip rift, you can choose for it to either be up to 60 feet away from you or be up to 10 feet tall and wide. You can expend a use of your Worldtear to only create one rift that lasts until the start of your next turn, which leads to a Worldfringe; any number of creatures can enter it, following the normal rules.

Also, you learn the teleportation circle spell, and can cast it only as a ritual; you ignore the spell's material components.

Living on the Edge

By the time you reach 17th level, each time you enter a Fringe, you can remain within it for up to 1 minute, and the first time you move through a Planar Slip or emerge from a Fringe, you can become invisible until the start of your next turn. The invisibility ends for you if you attack or cast a spell.