The Dakara superweapon is a hidden device capable of reducing all matter to its basic elemental components, and/or restructuring it. It was located at the Temple of Dakara, a holy site to the Free Jaffa Nation and the seat of its new government.
Possessing the ability to pass through the shields of all known ships (including those of the Asgard and Ori warships) it also functions (and has been used) as a devastating weapon to kill the entire crew of orbiting ships or wipe out all life on the surface of hundreds of planets at a time.
In August 2006, the temple of Dakara and the Dakara superweapon were destroyed by an Ori warship manned by Adria, the leader of the Ori forces and also the Orici, greatly weakening the Jaffa Free Nation.
The Temple of Dakara and the Dakara superweapon were built by the Ancients, the creators of the Stargate network. According to Anubis, it was once used by the Ancients to re-create the precursors of all current life in the galaxy, after the plague that wiped out the Ancients devastated the entire Milky Way Galaxy. Thus deeming it as a weapon is disputable.
Possibly for defensive purposes, the weapon was built into a considerably large mountain, into which a large carving of a seated pharaoh was carved. This was presumably done by the Goa'uld as a suitably ancient Egyptian symbol of power. At the seat of this mountain was the Temple, where the first Jaffa were allegedly created. (SG1: "Reckoning, Part 1", "Reckoning, Part 2", "Threads")
The device was located at the Temple of Dakara. It is said by all Jaffa that the Temple was the origin of their enslavement to the Goa'uld, the dominant race of the galaxy. At the Temple, Jaffa were first given their strength and symbiotes. The Temple is the ultimate holy ground of the Goa'uld, who keep the Jaffa loyal by propagating lies that they are gods. The very idea of stepping into Dakara was unthinkable as long as the Goa'uld controlled it.
The weapon itself was protected by a heavy door, in Ancient text stamped into five circles. These circles could be rotated, but only when the text is in the proper sequence will the door open and admit. Since many Ancient symbols mean completely different symbols when seen upside-down, the inscription can be interpreted any number of ways. This makes the door a giant combination lock, excluding anyone who doesn't have a thorough understanding of the Ancient language. (SG1: "Reckoning, Part 1", "Reckoning, Part 2")
The superweapon is designed to reduce all matter within range to its basic molecular structure (though in the case of Replicators the reduction is to their basic blocks for normal Replicators and probable large 'clumps' of nanites in Human-form Replicators). It does this by propagating a Replicator disruptor wave that breaks down matter at the molecular level. The wave will wash over everything on a planet's surface and in the surrounding space.
Its range is normally limited to Dakara and its surrounding space, however the wave will propagate through the wormhole of an active Stargate (unimpeded by either iris or Goa'uld shield technology) and expand on the far side to cover the planet's surface, but unlike Dakara itself, the wave will not propagate into orbit. Ba'al however modified the Dakara Stargate, using a 'hack' of the Dial Home Device's correlative update system to dial every Stargate in the Galaxy simultaneously, turning the weapon from a strategic threat to a Galactic scale superweapon against all planets within the Milky Way Stargate network.
The weapon is easily altered to fit one's needs. Its Ancient control panel has many blocks in a grid that may be moved lower or higher accordingly to alter the frequency output of the wave, which in turn corresponds to the type of matter that will be targeted and broken down. The default wave will break down any matter on the surface of the planet, originally intended by the Ancients to 'reset' the Galaxy after the plague killed off huge swathes of life. Anubis alludes to the weapon's ability to also reorganize matter into patterns that allowed life to evolve in some kind of controlled nature, as in the case of the Ancients' departure for the Pegasus Galaxy. The wave can be configured to target only living tissue, while leaving inorganic items like buildings and ships intact, as well as dead organic tissue such as clothing. This wave is also powerful enough to kill Priors. Replicators of both the Human form and traditional block form are vulnerable to the wave, though Lt. Colonel Samantha Carter was confident that they had just one shot with the wave configured to work against them before they would adapt (hence the hacking of the DHD to reach all the Replicators in the Galaxy at the same time, not letting any adapt and gain an immunity) (SG1: "Reckoning, Part 1", "Reckoning, Part 2")
The part of the Temple of Dakara which houses the weapon is protected by a shield which can withstand several direct hits from the main weapon of an Ori warship before succumbing. (SG1: "Counterstrike")
Created by the Ancients, the device was originally used to reseed the Milky Way after a plague wiped out most of the Ancients and forced them to leave with Atlantis to the Pegasus galaxy. When the Jaffa Rebellion took Dakara from Ba'al, he warned Brigadier General Jack O'Neill about the threat, and that Anubis was planning to use the weapon to wipe all life in the Milky Way. Lt. Colonel Samantha Carter and Jacob Carter intended to destroy the weapon, but with Ba'al's help, they used it to wipe out the Replicators including their leader, Replicator Carter who had been modeled on the original Carter. Anubis attempted to reuse the weapon, but Oma Desala engaged him in an eternal struggle to prevent him from doing so. After narrowly avoiding galactic disaster, it was agreed that the weapon was too dangerous to remain operational, and the Jaffa decided to destroy it. (SG1: "Reckoning, Part 1", "Reckoning, Part 2", "Threads")
However, the Jaffa never actually destroyed the weapon. Ba'al was aware of this and tried to take control of the Jaffa High Council, with the intention to use the weapon to obliterate all life in the galaxy except his own. With hardly any life left in this galaxy, the Ori would lose interest and ultimately abandon their plans to invade the Milky Way. (SG1: "Stronghold", "Insiders")
During the Ori invasion, the Free Jaffa Nation used the weapon to destroy the crew of an Ori warship. Adria, who had accompanied the ship, was protected against the effects of the weapon by a personal shield in her necklace. She was easily able to overcome the Jaffa and SG-1 who boarded the ship, and after having learned the position of the weapon, the only real threat to the Ori invasion, set a course for Dakara, completely destroying the weapon and killing many Jaffa. SG-1 were rescued by the Earth ship, the Odyssey before the weapon fired and Bra'tac of Chulak and Major General Henry Landry, who were both there to try to convince Se'tak to stop, managed to escape through the Stargate as the weapon was destroyed along with everyone else on Dakara. (SG1: "Counterstrike")
The ruins of Dakara were later seen once again as SG-1 was attempting to recover the Ark of Truth but they were ambushed by Ori warriors led by Vala Mal Doran's husband, Tomin and forced to surrender although SG-1 later escaped back to Earth, unharmed but found that the Ark of Truth that Dr. Daniel Jackson had uncovered was a fake. (SG1: "The Ark of Truth")