Both Gordon Freeman (through the Black Mesa's Lambda Core teleporter) and Barney Calhoun traveled to Xen through such a teleporter to escape from Black Mesa before its destruction. The portals can be used to travel between Xen and Earth, however, portals that allow for travel within the same dimension can be found across the facility, notably in the Lambda Reactor Core, which contains 9 portals, three on each of its three levels. Teleportation was a major field of study at Black Mesa, and their portals were used primarily in the procurement of Xen Crystals, as they were used to transport scientists to and from the Borderworld for research and analysis. Portals in the Lambda Reactor Core in the Lambda Complex. Another method was investigated by Black Mesa and later improved upon by the Resistance.

The most common and popular form of teleportation is via portals - essentially two connected gateways which allow an object entering one gateway to leave through the other. Via technological artifice, teleportation is usually achieved instantaneously.

Half life lambda core