The Reality Rifle was a weapon developed by Ytraxorian scientists during the Ytraxorian civil war. It had a psychic interface, connecting with its user on a physical and mental level. Physically, it resembled a conventional assault rifle, with the addition of organic weed-like fronds that integrated with the user.
The Rifle had many uses, being able to edit reality itself. It enabled its user to travel in time and space, although its space travel capacity was unreliable at best. It also was able to speed or slow down time within a specific area, enabling one to age or de-age their target to death. In addition, it could cause general destruction on a massive scale, being used by Cotter Gleason to destroy the White House. Like all Ytraxorian technology, it used Honour Filters to ensure only soldiers with a high level of skill could operate it.
The Reality Rifle was created by scientists on Ytraxor to aid in the civil war for their planet, which was gradually entering an Ice Age which was killing off its inhabitants.
One rifle eventually fell into the hands of Torchwood Three, having been claimed from the last surviving Ytraxorian soldier, who had used the weapon to transport himself away from his freezing world, dying soon after his arrival on Earth.
This rifle was one of a number of surplus alien items sold to the US government after the closure of all remaining branches of Torchwood. It was later used by a rogue military unit headed by Cotter Gleason, in an attempt to assassinate the President. They were stopped by Rex Matheson and Mr Wynter, who used the rifle to turn back time.