|Age||at least 800 (as given in Thief of Time, maybe even 6000 (The Discworld Companion)|
|Physical appearance||Skinny, bald, generic foreigner, tends to go unnoticed|
|Residence||Oi Dong Monastery, Ramtops|
|Books||Small Gods, Night Watch, Thief of Time, possibly Guards! Guards!, Going Postal and Raising Steam.|
Lu-Tze is a sweeper, but also goes on missions normally reserved for senior History Monks. That means that he makes sure that history happens the way it is supposed to. His function as a mere sweeper shouldn't allow that, but he has a special relationship with the Abbot of which little detail is revealed. It appears he has once started training as a monk, but didn't finish and went on to become a sweeper. Everything he learned, he did while sweeping classrooms.
In Thief of Time, Lu-Tze is identified by Kaos as one of his "Creatures". Lu-Tze's appearance is that of a hunched, harmless old man. He is always smiling and when asked a question he simply nods and continues with whatever he is doing. Which, usually, is sweeping the floor. Lu-Tze found out that nobody worries about a sweeper. Sweeping practically makes people invisible, and certainly anonymous. And a sweeper can get into the most restricted places, because even those places need to be cleaned. On occasion, however, he finds the anonymity undesirable and feels it is necessary to remind people of Rule One. While he claims the position of a sweeper, he is widely respected by many who know him, and feared by some. He is something of a legendary hero among the pupils and is the only known master of the art of Déjà Fu.
Lu-Tze is notoriously dismissive of other martial arts; his thoughts on them are as follows:
- Okidoki ('Just a bunch of bunny hops')
- Shiitake ('If I wanted to thrust my hand into hot sand, I'd go to the seaside')
- Upsidazi ('A waste of good bricks')
- Tung-pi ('Bad-tempered flower arranging').
- No Kando ('You made that one up').
It is not immediately clear who on the Discworld practices these arts, though they are mentioned in reference to the monks of time, who are known to practice martial arts in general.
While many cosmic harmony sort of high-ranking History Monks consider Lu-Tze unenlightened and annoying, and question his status, he is one of the best and most powerful when it comes to operations and training (though he does little of the latter). He's one of the most senior field operatives. He has seen it all, done it all, and still has not lost the interest in the people who make up history as they go along. In Small Gods Lu-Tze changed the path of history for the better, because he thought humanity could do without another war.
As a young man, Lu-Tze went to Ankh-Morpork where he saw a sign, and the sign was Rooms for Rent, Very Reasonable at Mrs. Cosmopilite's door. From her he learned The Way of Mrs. Cosmopilite with wisdom such as it only gets worse if you pick at it. In Thief of Time he takes his apprentice Lobsang Ludd to Ankh-Morpork to learn The Way, which turns out to be an excuse to go on a mission to stop the Glass Clock. The previous one was finished in Überwald just before Lu-Tze could stop it, a failure which still bothers the sweeper.
Lu-Tze is perhaps 6,000 years old (unless he's not; in daily conversations he claims to be 800 years old). This may be due to circular-aging, the History Monks' method of attaining longevity. It may also be due to the History being broken and then put back together too many times. He likes to grow Bonsai Mountains, which is a hobby that really needs patience and a lot of time (a couple of thousand years). He has his own area, the Garden of Five Surprises, in the monastery.
In Thief of Time it is revealed that Lu-Tze has apparently mastered the Yeti way of "saving one's life" to a time before death. This "saving" is dangerous as you have to die to see if it works and should thus only be used in the most dire situation. Lu-Tze got his head cut off by an avatar of the Auditors and was able, even in frozen time, to "load" his previous life and re-appear behind the Auditor. By the end of the book it also appears that he has been given additional life time as a gift from his departing apprentice, Lobsang Ludd, the anthropomorphic personification of Time.
A Sweeper is also the person with the broom, in a curling rink, who runs a little in advance of the moving stone, sweeping their broom backwards and forwards across its path. This melts a molecular thickness of the surface of the ice, giving the stone more speed and less curl, allowing an experienced sweeper to manipulate where the moving stone will finally come to rest. This is quite a good metaphor (on the Lies-To-Children level) for what the sweeper Lu-Tze does during the course of his field assignments for the History Monks...
A martial art called sna-fu is also mentioned and used by Lobsang in combat with the Auditors, although Lu-Tze does not comment on it. In military slang, snafu is a widely used acronym for Situation Normal - All F***ed Up
The name Lu Tze is close to Laozi, the Cantonese pronunciation of the name of the great Taoist sage Lau Tsu, a person famous for dismissing vanity and ambition and seeking a humble yet harmonious Way.