Competition instruction - how to complete your solving attempt
These guidelines will help you with completing your solving attempt. For more detailed information on this,
see Article A of the WCA regulations.
1. Sitting or standing?
When solving, you may choose to stand or sit. It's mostly a matter of personal preference, so choose whatever is more comfortable to you. If there's not a chair at your station, there might be one somewhere near, and you can simply pull it up. If there is a chair and you don't want it, push it aside. If you want to sit and there is no chair, ask your judge for one.
2. Inspection
Before you start to solve, you get to study the puzzle for 15 seconds. When you go up to the (competition) station, your puzzle will be covered. There will also be a Stackmat timer on the table. Don't touch anything yet! The judge will ask you "Ready?". Respond with "OK" or "Yes" or a nod of the head and the judge will uncover the puzzle. Pick it up and study it. Don't make any moves on it yet or you'll be disqualified. The judge will call out two things during this inspection. At 8 seconds, he/she will say "8 seconds". At 12 seconds, he/she will say "Go". Once he/she says "Go", you will need to start your solve very soon to avoid a penalty. Remember, the timer takes about 1 second to start up, and you will also take some time to put down the puzzle. You must start your solve within 15 seconds; the judge won't tell you anything after "Go" at 12 seconds.
Note: You have 15 seconds of inspection time, but you're not required to use the whole thing. If you're ready to solve after six seconds of inspection, start your solve.
3. Starting the timer
The timer used in WCA competitions is the Stackmat timer from Speedstacks.com. Before starting your solve, place both hands on the timer where the pictures of the hands are. When you do this, the red light will turn on. Leave both of your hands on until the green light turns on (about 1 second). Once the green light is on, you can remove your hands to pick up your puzzle and solve it. The red and green lights will flash while you're doing your solve.
While solving, avoid touching the timer, since doing so could stop it. If you're sitting down, make sure your forearms don't brush against the timer.
4. Solving the puzzle
Solve the puzzle. You came to the competition, so obviously you know how to do this, right? Good. If you happen to "pop" your puzzle (disassembling of the puzzle into many parts), then put it back together and finish the solve. If you get an "unsolvable" case when you get to the end, take the puzzle apart and fix the problem. When you finish your solve, put down a solved puzzle, or your result will be a 'Did Not Finish' (DNF in short). If you have 2 DNFs in a single round (1 for a Mean of 3 event format), you will not have an average and probably not proceed to the next round. Even if you have a slow time, always try to put down a solved puzzle.
5. Stopping the timer
Once you've solved your puzzle, put it down and put both hands on the timer. Stop the timer with both hands flat and palms down. Don't do a karate chop, don't use your wrists. If you quickly tap the timer and pick your hands up again, the timer may not stop. Put both hands on there and leave them on until the lights stop flashing.
6. Waiting
At this point, do not touch your puzzle or the timer. The judge is going to make sure that the puzzle is correctly solved, and then he/she will record the time from the timer. The judge will write down your time and then you sign (initials are also allowed) the score sheet. Do not sign unless you agree with what the judge has written.
Taken and edited from cubingUSA.com. (original) link valid as of January 19, 2013.
Related instructions: how to be a competitor and how to be a good judge.