Rune arm

Rune arms, also known as arm cannons, were ranged weapons used by artificers to fire blasts of magical energy.

Powers
A rune arm could be charged up to fire a blast of magical energy of a particular type. Although this didn't require much concentration, standing still and focusing allowed wielders to prepare far more powerful blasts, at the cost of a lengthier recharging period.

In addition, equipped rune arms passively enhanced other wielded weapons with the same kind of magical energy used for firing.

History
On Eberron, House Cannith was credited with the invention of rune arms. However, when adventuring artificers from this world crossed over to Toril in the, they were able to find that numerous rune arms already existed there.

Notable Rune Arms

 * An unnamed archaic device, a rune arm that converted incoming elemental damage into blasts of force.
 * Arc welder, an electricity-shooting variety of rune arm intended for welding metals together.
 * Corruption of Nature, an acid-spitting rune arm that conferred a more benign version of red musk creeper infection to its wielder.

Appearances

 * Video Games
 * Dungeons & Dragons Online