Everybody can participate in challenges open for submission. You simply

1. Choose one or all of the current challenges
2. Read the challenge description(s), which may vary in their rules (e.g., some place restrictions on when the photos are taken)
3. Take picture(s) for the challenge(s) during the challenge period (or, if allowed, select from your own existing pictures that are not yet on Commons)
4. Upload your picture(s) during the challenge period
5. Submit your candidates at the top of the current challenge gallery during the challenge period. To do that you click the [Edit] button of the Entries section of your chosen challenge and insert the File name above the last entry (or above File:-Insert image here-.svg for the first entry).

   Add your entry between the <gallery> tags as indicated. Gallery entries are placed each on a new line, and consist of the filename, a vertical bar |, and a description. For example:

   Electric steam iron.jpg|An electric steam iron

   For help on the syntax of entries in a gallery see Help:Gallery tag. Please do not add square brackets [[ ]] or include a thumb parameter or the full URL. The File: prefix is not required, but harmless.

6. Do not sign your submission(s)
7. If you want, you can have a look at previous challenges and Vote

Challenges are open to any Commons user. Submissions must be your own work, not previously uploaded to Commons prior to the challenge date and should illustrate the challenge theme in the opinion of the photographer. Please read the challenge descriptions, as there may be additional rules or explanations for specific challenges. There is no limit on the number of submissions per user (unless specially so restricted in the challenge), but please choose from among your best and most varied images.