First and foremost, you must be the creator of a comic that is available to be read online.
You must have at least 20 comics in your archive.
A "comic" refers to an actual comic strip or page, not a dead artist day, a random sketch showing a possible future character, a tribute, or so forth. This number of comics does not include guest comics for/by other people. This count will be checked prior to a comic's approval.
Your comic must be currently active, not completed or abandoned.
If your comic is complete, retired, or abandoned, then it is considered inactive and does not qualify. (Comics that are on temporary hiatus may participate.) If you have two comics, one inactive and one currently updating, then you may submit the current one.
You must adhere to the schedule and commitment.
This activity does require effort on your part. By signing up for the Web Comic Secret Santa, you agree to produce gift-work for the comic to which you are assigned, and you must commit yourself to the schedule given.
You do not tell people who you got until the date that you can reveal yourself to your recepient.
Otherwise, that ruins the whole point of it being the Secret Santa.
Your comic must be easy for everyone to access.
The creator drawing gift art for your comic must be able to easily access your comic archives for reference. Since this is intended to be a fun activity and participants are not paid, your archive should be free and easy to view for the creator drawing your gift art.
No sprite comics.
The previous Web Comic Secret Santa administrator received complaints on this issue, so sprite comics are excluded.
The organizer has the right to reject a submitted comic for any reason.
This is a catch-all rule, but do not be afraid. The purpose of the Web Comic Secret Santa Exchange is to have fun and this rule is just in case a comic does not seem to be submitted for the purpose of the comic's creator to have fun.
Do you have a question that is not answered above? Please feel free to use the comment form to ask!