Tiberium is presented as a double-edged sword within the context of the story arc of the respective video games. While it is the greatest mineral resource ever encountered, conveniently gathering many potent elements into an easily harvestable form, it also brings with it considerable hazards: areas rich with the rapidly spreading Tiberium substance are eventually exhausted of their native ecosystems, and become too toxic to support normal carbon-based life. In the context of the gameplay, Tiberium can also be seen this way with its obvious tactical advantage as a resource, and its destructive effect on infantry, sometimes transmuting them into Visceroids.

Tiberium can be thought of as, in effect, a commodity, with everything that one builds in the game costing Tiberium-based credits. It can appear anywhere on Earth, but spreads much more slowly in areas of extreme cold climate. In Tiberian Dawn and Tiberian Sun, it will spread very slowly in-game but primarily comes from special Tiberium-generating Blossom Trees, infested trees that release Tiberium spores into the air; in Tiberium Wars, these trees are replaced by Tiberium Fissures in the Earth's crust, and Tiberium will not spread outside a certain radius of these fissures. Either way, it is harvested by vehicles called harvesters. As a currency, Tiberium is collected to build structures and to train units..

The substance is named as such because it was first discovered near the river Tiber in Italy. Kane, who claims it was in fact the Brotherhood who first discovered Tiberium, states that he himself named it after Tiberius Drusus Julius Caesar.

Conception

Tiberium was first introduced in the original 1995 Command & Conquer game to replace the "spice" from Dune II as the mined resource for building and expanding, and was inspired by the 1957 B-movie "The Monolith Monsters". According to Westwood Studios co-founder Louis Castle "It solved one of the fundamental problems we had with making an RTS, which was that we wanted to have a central resource that everybody was fighting over. Dune has spice, which made perfect sense - and it was also used when we came to the idea of Tiberium. It became the anchor of the C&C universe because people were arguing over a limited resource that represented wealth and power".

In Tiberian Dawn, Tiberium is said to be composed of 42.5% phosphorus, 32.5% iron, 15.25% calcium, 5.75% copper, 2.5% silica, and 1.5% unknown substances. Its gaseous emissions are composed of 22% methane, 19% sulfur, 12% naphthalene, 10% argon, 6% isobutane, 2% xylene, and 29% unknown gases.

For the development of Command & Conquer 3: Tiberium Wars, Electronic Arts decided to radically alter its composition, and commissioned scientists from the Massachusetts Institute of Technology to provide a white paper describing the biophysics of Tiberium, its atomic structure, its method of transmutation, the form of the radiation that it emits, and the way to harness it for powering machinery and weapons — giving it the same treatment as would be suitable for a scientific journal article on a real substance.