Moongate

In the Ultima game universe, a moongate is a magical means of space or time travel that can be used to go to any place or time.

There are 4 kinds of moongates:

• Blue - These will transport one across the world. Requires a buried moonstone. Will activate at the proper bi-lunar alignment to a set destination. †
• Red - Requires an Orb of the Moons. Only 2 Orbs were known to exist, but activation allowed for travel to any destination, which was determined by where the Orb was used. These allow the traveller to travel across worlds, most notably between Earth and Britannia.
• White - A rare form of moongate. It allows time travel. The Time Lord was able to create them and they were involved in the pursuit of Minax in Ultima II.
• Black - This type of moongate requires electrically charged blackrock. These types of moongate were favored by the final enemy of the Avatar, who was known as the Guardian, as they allow travel between dimensions.

† - Note: Britannia has 2 moons, Felucca and Trammel.