Wildfire

Wildfire is a volatile, jade-green incendiary substance produced by the secretive Alchemists' Guild of King's Landing. Known as the substance, it burns with an unnatural ferocity that water cannot quench, and it is among the most dangerous weapons in Westeros.

Properties

Wildfire is a thick, glowing green liquid that, once kindled, burns so hot it can melt stone and so fiercely that water only spreads it. Only sand, earth, or sheer smothering can put it out. It is extremely unstable, especially as it ages, and can ignite from rough handling, heat, or even seemingly on its own, making its storage perilous. The pyromancers of the Alchemists' Guild guard the secret of its making, which they cloak in claims of spells, though they hint its potency once owed something to the magic of living dragons.

The Mad King

King Aerys II Targaryen, the Mad King, grew obsessed with wildfire and had vast caches of it secretly buried beneath King's Landing, including under the Red Keep and the Sept of Baelor. In his madness he meant to burn the whole city rather than yield it, a plot foiled when his own Kingsguard, Jaime Lannister, slew him during the Sack of King's Landing.

The Battle of the Blackwater

The most spectacular use of wildfire came at the Battle of the Blackwater, when Tyrion Lannister loosed thousands of jars of it upon the fleet of Stannis Baratheon in the Blackwater Rush. A single fire arrow ignited the green flood, immolating Stannis's ships in a roaring wall of jade fire and saving the city.