Displacer Cannon

The displacer is a type of extremely compact and portable teleportation machine that was developed at the Black Mesa Research Facility. The displacer could also be used a weapon, the Displacer Cannon. A displacer has two different modes: the first generates a displacement field (or portal) ahead of the user, allowing the teleportation of a single object, person or being. The alternate mode generates a portal behind the emitters, teleporting the displacer and the device’s user.

The portals generated by displacers were somewhat unique compared to other teleportation technology, as they did not have to be maintained by a constant supply of displacement energy; instead the displacement field was given a large amount of energy in a concentrated burst, allowing the portal to remain open for some time before the portal’s energy was depleted. To generate this degree of energy within such a compact device required a Xen crystal or some other imitation with exotic matter properties. The other key component was a micro-fusion reactor fuelled by depleted uranium, also used in the tau cannon and gluon gun weapons that were developed at Black Mesa.

A moving displacer portal will travel in a straight line in defiance of gravity, teleporting the air and dust particles that it passes through, as they do not significantly deplete the displacement energy. This process will ionise the air and can result in a form lightning to arc between the portal and objects that it passes, a hazard that displacer operators must be conscious of. When the portal comes into contact with a significant amount of mass, it will lose enough energy to destabilise and collapse. In the brief moment before this occurs the matter in contact with the portal will be teleported, unless its mass exceeds the limits of the displacement field. This limit tends to be slightly greater than the mass of a human being; larger creatures, vehicles, dense objects or walls cannot be transported.

When the portal collapses it causes a displacement shockwave, a wave of extremely dangerous space-time distortions, anomalies and exotic particles that will damage the structure of matter. When a displacer is used as a tool to teleport objects, people or beings, care must be taken that there is no one near that could be harmed by the shockwave, or objects that could sustain damage. A shockwave is also left in the wake of the displacer’s self-teleport feature, and so safety precautions must still be taken.

The dangerous aspects of displacer technology also allow it to be used as a powerful weapon, and for this reason the device is sometimes known as the Displacer Cannon. The user can purposely fire a portal near to an enemy or into the midst of a group of enemies; firstly the arcs of lightning may cause some harm, and then when the portal collapses after hitting the ground or wall the shockwave is capable of eliminating several human-sized targets. Additionally the teleportation destination can be set to send anything it hits to an undesirable or dangerous location.

Corporal Adrian Shephard, a member of the Hazardous Environment Combat Unit sent into Black Mesa, found a displacer after being teleported to the Xen border world. The device appeared high in the air, along with the scientist who activated it, presumably in an attempt to escape from some threat. The scientist was killed by the fall but Adrian was able to retrieve the device and use it as a weapon. After teleporting enemies Adrian never encountered those individuals again, and when he activated the device’s self-teleport feature he was sent to a different random location each time, usually in the Xen border world. It is possible that the prototype displacer had no means of choosing a destination, or that the destination was supposed to be pre-set by some external method, and this was disrupted by the dimensional rift at Black Mesa. Since Shephard was a soldier rather than a scientist trained in teleportation technology it is also possible that there was some kind of control mechanism that he simply did not have the skill to operate.

The compact teleportation technology of the displacer appears to have been lost, since the teleporters built recently by the Resistance against the Combine are far larger than displacers, but it is possible that portable teleporters may eventually be developed once again.

The Displacer/Displacer Cannon is a weapon in Half-Life: Opposing Force.

''In single-player, a direct hit from the portal (or 'displacer ball') the weapon fires will remove most enemies from the game, although some of the larger creatures can survive. If the portal passes an NPC while flying through the air then the portal may cause damage to the NPC with white, lightning-like beams. After the portal hits something it vanishes and causes a shockwave that does a large amount of damage to anything that surrounds it. The alternate fire mode will cause the player to be teleported to another location in the map; usually there is some health, armour or ammunition to be found there but occasionally the teleport destination can be deadly, so saving the game before attempting a self-teleport is recommended.''

''In multi-player, the behaviour of the weapon is slightly altered; if a player is directly hit by a displacer ball then the player is not killed but instead teleported to a random spawn point in the map. Similarly, if the weapon's user activates the alternate fire mode then the user is teleported to a random spawn point. This departure can damage or kill nearby players as a shockwave is created as the displacer-user disappears.''

''The 'displacer ball' portal has the appearence of teleport portal exit (mostly green with an orange core) rather than a portal entrance (mostly orange with a green core). This could be considered an error, or alternatively it may be a side-effect of the unstable nature of the portal generated by a displacer.''