Antarctica Starts Here.

Game: Mage: the Ascension
Rote: Portal Gun (alternatively, Artifact *)
Spheres: Correspondence *
Tradition: Sons of Ether
Commonly used focus: Self explanatory

Effect: The Virtual Adepts came up with it but it took the Sons of Ether to make it practical. Nobody's quite sure if Valve only has Sleepers on staff or if there are a couple of VA's among their coders, but everyone agrees that having a device that can forge Correspondence portals in the blink of an eye is a handy thing, albeit horribly vulgar. While gamers eat this stuff up like cake using one of these badboys outside is a good way for a mage to garner lots of paradox fast.

Persistent rumors that technomagical artifacts which do not require a mage's arete to function circulate within the Traditions as well as the Technocratic Conventions, but it seems like everybody knows somebody who knows somebody who claims to have constructed one...

Mechanics: As a rote, three successes are required to construct a stable Correspondence portal between two points within the character's line of sight. Fewer successes result in portals that spontaneously collapse after a number of rounds equal to the number of successes rolled. The character can close the portals whenever the player chooses. Use the standard rules of whichever edition of Mage you're playing to determine how much paradox the character accumulates.

Artifact: As the rote, only the you use the artifact's inherent arete of four dice to determine success. The Portal Gun artifact starts out with a quintessence pool of twelve; one unit of quintessence is consumed each time the gun is used (i.e., for every two firings, one for each end of the Correspondence gate). Additional units of quintessence may be burned by the character for extra grades of success. The gun accumulates quintessence according to the vulgar magic rules of whatever edition of Mage you're playing. A paradox backlash means that the gun shorts out and must be repaired; whether or not active portals continue to exist is left to the whims of the Storyteller.