Artefact (Final Fantasy XIII-2)

Artefacts are an important element of the gameplay of Final Fantasy XIII-2 and the Historia Crux. When acquired, they allow use of Time Gates, which act as portals to the Historia Crux, the travelling element of the game. Time Gates are said to appear whenever there is a distortion in time, but they can only be accessed through use of specific Artefacts, specific to each gate. Since Artefacts are not supposed to exist, due to being formed when two timelines collide, they can only be uncovered by use of the Moogle Throw command.

Time Gates
Multiple time gates can appear in each location, but each leads to a different world.