In technical theatre this term is given to the person who has to run about and find what are commonly known as props.
The Properties Master begins to collect items for use as soon as actors start rehersal. Rehersal props are roughly the same size and shape of props that are actually going to be used, but are usually not what will be used in the play itself. For example, a cigarette is often replaced by a short pencil during rehersals because no one wants to sit and waste cigarettes rehersing the same scene over and over.
They are also forced to put up with really random unforseen events during shows. In one particualarily memorable situation a theatre company decided that they wanted a live horse on stage for one of their shows. Just before intermission the horse laid down and went to sleep. Once the curtain went down they figured that they should wake the horse up and get him food and water to revive him for the second act. They quickly realized that the horse was not asleep, but dead. After a ten minute debate it was decided that the horse did not count as a set piece, but rather as a prop and it was left to the props team to drag the dead horse from the building.
A Properties Master spends a lot of time working in the theatre or shopping for props. As simple as it may seem to find small objects, I have never seen a show with less than 20 props at any one time and I have never seen a show where no props had to be hand-made. Truly fantastic Properties Masters can turn almost any object into a prop. They can put MacGyver to shame with their ability to use a little bit of paint or cardboard to make any object into anything from a notebook to a couch. they also have to be able to do this very spur of the moment.
The best example I can give of this was from a few summers back when I was working on the show Anne Of Green Gables. At several points in the play a bush came on as a bit of scenery. After one scene an actor running to catch a cue tripped over the wooden bush and broke it to pieces. In a few scenes there was a part in the play where Anne is supposedly sitting in a boat that gets pushed into water. In our version she just got pushed out of sight behind this bush. Big problem. Our Properties Master looked at the mess and said, "Go to the dressing rooms and get me as much green fabric as you can, run to the office and get green spike tape, run to the props room and get me fake flowers and then find me a stage hand with nothing to do for the next two scene changes."
Properties Masters are often overlooked and under-rated, so next time you see a frazzled techie hastily painting a blue plate red to match a banner strung up behind them, give them a hug.