Queue dodging

Queue dodging is the act of leaving the champion select screen by interrupting the connection with the server. The act is generally frowned upon and the player is penalized by the system. There are various reasons why people queue dodge, generally because they are not content with the champion selection.

Sometimes queue dodging is not intentional, but instead the result of a connection loss, computer crash, or other technical mishap.

Methods
The most common and easiest method to queue dodge is to close the client. This is done using the 'X'-button in the top right corner or using ALT+F4.

Other methods include disabling the connection with the internet, removing power from your computer, or otherwise disrupting the connection. These are more drastic measures that may damage your computer.

Penalties
Penalties for queue dodging vary according to the game type.

Normal penalties
5 minutes, 10 minutes, etc. depending on how often you have queue dodged recently.

Ranked penalties
Loss of 10 Elo and a queue dodge penalty timer.

Reasons
The primary reason why people queue dodge is because of the selected champions. They might not feel playing against a certain champion or team composition or the other way around: they have the feeling that the team or champion they are forced to play with won't be good enough to secure a victory.

Also one might have the desire to play with an already selected champion. This is often the case when a new champion is released or in free week and many people want to try him out. This might result in a vicious circle. Someone picks this champion first causing another person to leave. The game is disbanded and the same happens again in the next game. This might go on for some time, causing long times before people can actually play.

Another reason why one might leave is an external factor. Besides the obvious technical problems (connection loss, computer crash...) that causes a queue dodge, there might be reasons like: friends came online while this person is in champion select and he decided it was worth it to receive a penalty in order to be able to play with them. Others include being unexpectedly called away from the computer and others..

How to avoid
Check the stability of your system in order to prevent errors, crashes and other problems. You might want to close other applications to reduce the risk of this happening.
 * Individual prevention

If the game is constantly crashing during champion selection, The League of Legends repair tool can fix most crashes and issues with the game.
 * Preventing others from quedodging in normal

Talk during champion selection is important in reducing the chance there will be a quedodger. Creating a positive environment in which summoners feel comfortable to talk about their builds in is ideal.

Remember that normal games are unranked, and it is a mode for testing out builds/ideas and having fun.

After a number of quedodges, simply type in something complaining about quedodgers. This frequently encourage teammates to stay.