The contest is made up of multiple categories. Each category is worth one point toward the total score; your team's score in a category is the fraction of the total points unlocked so far in 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.
When points are unlocked in a category, every other team's score in that category goes down until they too score that point. Unlike previous years, however, unlocking points is the only way to reduce another team's score.
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 receive 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 points. They take on two forms: a single or multipoint token. A single point token for the "example" category might look like this:
example:xylep-radar-nanox
A 42 point token for the "example" category might look like this:
example:42:xihyp-ropar-nanix
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.
Many Capture The Flag contests attempt to reward teams who answer quickly, by adding a "quick answer" bonus or by decaying point values over time. Our contest doesn't work this way.
We want to focus on rewarding technical proficiency, allowing skilled contestants to prove their worth independent of their ability to hit F5 quickly. It is our hope that by providing enough things to work on, quick-moving teams will emerge with more points by solving lots of puzzles, while novice teams get a solid benchmark against which to judge their technical skill level: you don't have to make allowances for reaction time in comparing scores. 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.