The Millennium Falcon is a starship in the fictional Star Wars universe, piloted by Han Solo and Chewbacca after Solo apparently won it from Lando Calrissian on a bet. The ship was chartered by Obi-Wan Kenobi and Luke Skywalker to deliver R2-D2 and the stolen Death Star plans to Alderaan.
When challenged by Obi-Wan about his ship's speed, Solo famously replied, "Fast enough for you, old man." The ship is capable of attaining "point five past lightspeed."
Han's famous comment, that the vessel "made the Kessel run in less than twelve parsecs," comes off a little incongruous -- a parsec is a measure of distance, not time. It has been conjectured that George Lucas simply did not know that when he wrote the script. In the 4 DVD special edition of the original trilogy, Lucas explains that the remark meant that the Falcon's computer was so advanced that it was able to plot a shorter route through hyperspace than any other ship, and thus travel faster. An alternate explanation is that Solo was most likely trying to impress his travellers with plausible-sounding yet meaningless bragging. Some novelizations have retconned the statement as meaning that Captain Solo was able to hug closer to the black hole cluster known as the Maw, shaving off distance (and thus time).
At sublight velocities, the Millennium Falcon is not a particularly fast vessel; Imperial Star Destroyers have been able to keep up with her. However, the Falcon was considerably more manuverable than Star Destroyers. An example of this is when Han Solo used the manuverability to elude three Star Destroyers that were trying to block them in and nearly made them collide with each other. The Falcon's true strength involves the skill of her crew and her extraordinarily fast supralight speeds, of which no manned vessel is known to compare.
The cobbled-together nature of the ship presented many problems throughout the movies and the novels; systems were barely held together and apparently had many incompatibilities. C-3PO once commented that he wasn't quite sure where the ship learned to communicate. During Imperial pursuit from Hoth the ship's technical difficulties—namely an inability to enter hyperspace—resulted in the ship and crew nearly being captured.
Years after the Battle of Endor it appeared that Han Solo and/or Chewbacca were able to resolve these difficulties, much to the relief of one Leia Organa-Solo. The resolution of those problems may have involved a virtual rebuild of her internal operation systems; this has never been discussed in detail.
The ship sports quad blasters startlingly reminiscent of World War II crew-operated machine guns, with the operator tracking targets optically (due to the high prevalence of electronic warfare in Star Wars) and swiveling along with the gun barrel. In Return of the Jedi, the ship is revealed to possess powerful armor-piercing missile weapons called "Concussion Missiles," which are illegal in the Star Wars universe for civilians (like smuggler pilot Han Solo) to possess. During the events surrounding the reborn Emperor Palpatine, the missile launchers were temporarily replaced by a giant lightning gun. Later refits, during her service as a New Republic diplomatic courier for the Organa-Skywalker-Solo family, who were highly placed in the New Republic in honor of their service to the Rebellion during the Galactic Civil War, included light turbolasers replacing her quad blasters. At least one pop-out repeating blaster is mounted to give some ground cover when the use of the heavier weapons is not warranted.
The ship has been captured by the Death Star's tractor beam and searched by Imperial Stormtroopers, who managed to miss the crew and passengers secreted in the smuggling holds, which are shielded against most scanning equipment. It has also been piloted through asteroid fields, and on one occasion (miraculously) outran the massive explosion of the second Death Star.
The ship played vital roles in both of the Death Star battles.
In Expanded Universe material, it is referred to as a highly-modified YT-1300 freighter. The ship has three droid brains. It was won by Han Solo in a Sabaac Tournament in Cloud City. The previous owner was Lando Calrissian. After the end of the movies, the ship becomes a New Republic diplomatic courier for the Skywalker-Organa-Solo family, and is comprehensively refit with military-grade power generators, propulsion and weaponry.
In Episode 3 - Revenge of the Sith - the Falcon will have a brief onscreen cameo appearance, but as a brand new, freshly-built state-of-the-art spacecraft. Other ships of its class appeared in The Phantom Menace (they are briefly seen at the Naboo spaceport).
In real life, the original model for the Millennium Falcon was changed at the last minute because it too closely resembled ships from the television series Space: 1999. The replacement is said to be based on a half-eaten hamburger held by George Lucas and the disused original design was further developed into the Blockade Runner starship seen at the beginning of the first film. Like many science fiction spacecraft, the Falcon's interior sets can not actually physically fit within the exterior sets. Subsequent extended universe plans are consequently a compromise attempt at squeezing the interiors in (often with detriment to headroom).
