Leygate

Leygates are magical edifices designed to tap directly into ley lines in order to open a permanent portal between two locations. Leygates are typically constructed from magical stones and metals, such as truestone, in order to safely channel the required amount of mana necessary for a portal to remain open indefinitely.

Overview
In order for a leygate to function properly, it must be inscribed with a combination of various types of arcane runes. The first step is to locate the ley line upon which the gate will be built. The bigger the ley line the more mana that can be channeled through the leygate, which allows for further distances to be traveled.

Second, the construction material must be magical in nature, and is typically made from stone or metal. Wood can be used in the construction of leygates, but its durability leaves much to be desired, and the abundance of magical woods that are tough enough to withstand the constant barrage of arcane energies is limited. The most common types of materials used are truestone, sinmetal, adamantine, and eternium. Though this is far from an exhaustive list.

The third step is to inscribe the materials with a very specific set of arcane runes, which will allow the leygate to draw in the necessary amounts of mana, and open a portal to the desired location. These runes, when finished, meld into the stonework and become undetectable without the use of true sight or magical scrying.

After all is done, the leygate is merely activated by shunting enough mana to activate the runes located on its structure. To choose a destination, the user must simply think of the desired location while funneling mana into its runes. If enough mana can be pulled from the ley line, then the portal activates. The portal will stay open indefinitely unless told otherwise.

Due to the sheer amount of arcane energy required to open and maintain a leygate, portals that are left open will eventually harm its environment. The land will become cracked and weathered, its plant life wilting and dying. Animal life will begin to suffer mutation, becoming twisted and horrid in appearance. The extent of the leygate's effect on its environment is directly proportional to the distance the portal crosses.

Additionally, opening more than one portal per ley line is a dangerous affair. The construction and activation of multiple leygates on a single ley line can cause the ley line to explode. This explosion can very easily cause a chain reaction beneath the planet's surface, causing it to blast itself apart. More than one planet has met its demise at the hands of careless use of leygates. Planets destroyed in this fashion are commonly known as "outlands".

Usage
The construction of leygates is an art known by very few. The Black Order is famed for their construction of "demon portals"; massive leygates that allow the Order to move entire armies between worlds. It is through demon portals that the Black Order is able to maintain its grip on the thousands of worlds they have conquered. Demon portals are also the primary method through which the Black Order invades other planets. Typically, this is done by manipulating a mortal mage into building a leygate. At which point the portal activates, and a demonic vanguard quickly follows through.

The city of Daramaar has a large metallic device similar to a leygate, known as the Dimensional Portal. This large round metallic structure siphons mana from multiple ley lines, thus reducing the chance of an catastrophic overload. The Shadra Torr have used this device to visit several worlds already, though its use is tightly controlled by the archmagi.