The contest is made up of multiple categories. Each category is worth one point toward the total score; the percentage of the total points held by your team is the percentage of one point your team has for that category. The team that has 30% of the points in each of five categories has 1.5 points, whereas the team that has 80% of the points in only one category has 0.8 points. It is typically better to have a few points in many categories, than many points in a few categories.
There are two main ways to make points: puzzles and tokens. Your contest may have other ways to make points: these will either be automatic, or explained elsewhere.
Many of the categories are in the form of multiple puzzles: for each puzzle presented, a case-sensitive answer must be found to recieve the amount of points that puzzle is worth. Any team may answer any puzzle question at any time. A new puzzle is revealed when a team correctly answers the highest-valued puzzle in that category.
Tokens are strings redeemable once for a single point each. A token for the "example" category might look like this:
example:xenon-codex
Tokens are typically associated with "live" categories, such as a network-based service or a treasure hunt. Tokens can be submitted with the form on the welcome page, or you can write your own script to automate token submission.
Some tokens change periodically, typically once a minute. If you find a token, it's worth looking in the same place again later to see if the token changes.
The scoreboard shows total score on the left, and scores within each category. If you have a smaller or more novice team, you may wish to ignore total rankings and strive to do well within only a few categories.
If your browser supports the HTML5 canvas (Firefox, Safari, Chrome, Opera, iPhone, Android) and JavaScript, the scoreboard will also have a graph of scores over time. Additionally, JavaScript-enabled browsers will highlight all point blocks belonging to a team, and a team's line on the graph, when the mouse cursor is over a point block.
Many Capture The Flag contests attempt to reward teams who answer quickly with more points, by adding a "quick answer" bonus or decaying point values over time. Our contest doesn't work this way.
We believe that given enough things to work on, quick-moving teams will emerge with more points by answering more questions; while providing novice teams a realistic picture of how they're doing. In addition, when the game infrastructure goes down—which seems to happen a lot in anybody's CTF—there's no losing points while the organizers struggle to get things back up.