From the 20Q home page, select Play from the menu on the left, and then "Play 20Q" from the menu that will appear in the top.

The main frame of the window will then allow you to select which language to play in by presenting a list of flags corresponding to the currently supported languages. Choose one of the lanugages, and then on the next page, answer the brief demographic questions and click "Play".

Next, think of an object and answer the questions asked by the Artifical Intelligence (A.I.). Beginning with the question: "Is it classified as Animal, Vegetable, Mineral, Other or Unknown?", you will notice five possible answers below the question.

Click on the answer that fits the object you chose. The subsequent questions will be displayed by the A.I. with several choices. Click on what you believe to be the appropriate answer for that question.

Don't worry about making a mistake, you can always scroll down and click on the questions to change your answer later.

When you arrive at 20Q, you are presented with a number of Flags which are labelled "Think in ..."

When you choose one of the flags, you are telling the game which knowledge base to use. Each language that the A.I. can play in has it's own independent knowledge base because different cultures think about the world differently. A North American thinks of the baggage compartment of their vehicle as a 'trunk', but someone from the U.K. would call that a 'boot'.

After you choose the knowledge base you want to use by picking one of the flags, you are asked for some minimal demographic information, including your geographic location. It is therefore possible to play using the Greek knowledge base even if you live in North America.

You may change your answer to a question while playing the game. Select the question from the list of answered questions, then change your answer. You may also use the back button of your web browser, but the A.I. may pick different questions than it chose the first time.

Once the Update button has been pressed, the knowledgebase is permanently modified by the answers you gave it and you won't be able to go back. Don't despair. Every game changes the knowledgebase a little bit; the game will be corrected over time by you or other people playing the game.

Sometimes when you get to the end of a game, the A.I. will tell you that there were contradictions. You may notice that the A.I. can be wrong. This happens because the A.I. tries to reflect human knowledge, not necessarily facts. The one way to correct such "errors" is to play the game thinking about the same object again and again and again. The A.I. will eventually learn the correct answer after a few games.

We always like to hear about typos and other strange problems. Please fill out our contact form and let us know if you find any such problems.

When the A.I. suggests you have made some contradictions at the end of the game, it is merely giving you a peek into its state of mind with regard to the object you played. Since the A.I. learns everything it knows from the people who play it, it is dealing with opinions and not facts.

Since peoples opinions often differ, the A.I. must do its best to sort out conflicting information. Contradictions are also one of the main ways that the A.I. learns more about something. If enough people contradict what it currently thinks, it slowly changes its mind about that subject and eventually the contradictions will no longer happen.

You are playing twenty questions with the A.I. and it seems to be asking somewhat relevant questions and then, out of the blue, it asks a question that is completely unrelated. When the A.I. picks a new question, it uses the answers you have given it and looks for probable objects. It then looks at its knowledge of those objects to determine which question would rule out as many objects as possible. Sometimes the A.I. will find a question for which it has very few answers; it may ask one of these questions to fill-in the knowledgebase.

The bottom line is, the question may seem obviously unrelated to you, however, the A.I. wants to ask the question since that's how it learns.

If at the end of a game, the A.I. doesn't know your object you will have an opportunity to provide it. The next time you play, the A.I. may still not know the object and you may need to tell it again.

Why? When you tell the A.I. what your object is, the object and your game are placed in a queue of objects to be reviewed by a group of human moderators. A moderator will review the object you entered and either change your answer to something the game knows or add your object to the knowledgebase. If the object is added to the knowledgebase, two other moderators will review the object and must agree it is a worthwhile addition before it is made available for play.

One hint; the objects that have been played most often will be reviewed first (this means that you can speed-up your object's acceptance by playing it several times).

The objects that are added to the knowledge base are censored. The moderators assign a censorship level to each new object and question. The A.I. will not choose questions or guess objects above the player's current censorship level.

If you are playing as anonymous, the game will be G rated (suitable for all audiences). If you become a member, you may change your rating level from the options page.

The membership sign up page is currently disabled. We are currently working on a new membership system that will allow many more options than our previous system, and will also allow a much higher number of people to sign up.

If the A.I. knows a lot about an object, it will often guess it in less than twenty questions. The reason it will ask up to thirty questions is to help its knowledgebase grow faster. The only way the A.I. can learn is by asking questions; the more questions it asks, the faster it learns. You can always tell the A.I. to give-up after it has asked twenty questions or more.

The A.I. will not count questions to which you answer Unknown. The rationale is, if you do not know the answer, the A.I. cannot use the information to guess at an object. You may answer as many questions as you like with Unknown, since the AI has lots of other questions it can ask.

You are allowed to answer as many questions as you like choosing Unknown as an answer, but if you answer too many questions with Unknown, the A.I. will start to forget about some of the questions that you have answered with Unknown. The A.I. limits the number of answers that it can store to 50, so to avoid over-filling its answer buffer, it will forget your first Unknown answers.

The game will go into 'sleep' mode after 60 seconds of inactivity. To wake the game up and resume your game where it left off, simply press the "YES" button.

The game is powered by two AAA (LR03) batteries. To replace them, you must remove the back cover of the game using a screwdriver. Loosen the screw in the center of the back of the game until the battery compartment door can be removed. Remove the old batteries, and replace them with fresh ones as indicated by the markings inside the battery holder, then replace the back of the unit, and gently tighten the screw.

You should bring the game back to the store where you bought it along with your receipt. Most stores will be happy to exchange a defective game for a working unit. You can also contact Radica (in North America) at 1-800-803-9611 for information on returning a defective unit.

The answer depends on which carrier you are subscribed with, and what area of the world you live in. the best way to find out about the availability of 20Q Mobile on your carrier and phone is to go to I-play and use their purchase mechanic. Some carriers also have websites where you can go to see which games are available for their phones. This is also a good place to look.

20Q.net Inc. is working with I-play, one of the largest mobile content providers in the world, to produce mobile versions of the game that will cover many of our supported languages. As work is completed on these other versions, the game will be made available in more regions and on more carriers worldwide. Check the I-play website, or check with your carrier frequently to see when it becomes available for your phone.