💡 Hints
A hint is a short tip, advice or suggestion that can be given to contestants for a challenge for helping them solve the challenge. A challenge can have multiple hints, which can either be freely accessed or it might involve certain cost points that will be deducted from the contestant's total score.
Cost
Hints can optionally have cost to unlock. For such hints, the contestant would have to unlock the hint for some points, and receive a corresponding drop in score equal to the score of the hint. By default, the cost of hint is set to 0 (free), and they do not require explicit unlocking.
The organizer has the option to allow debt for hints in the settings, which allows contestants to unlock hints even if they have not earned enough points to do so. In this case, the score of the contestant shall drop below zero (i.e. become negative).
By default, if a contestant does not have enough points to unlock a hint, they will be unable to unlock the hint, and their score shall not be allowed to go below zero to unlock a hint.
A simple strategy is to have a "welcome"/ "sanity" challenge with some points that will allow the contestant to gain some free points which can then be used to unlock hints in later challenges.
If your CTF has open registration, and no verification process, users may be able to create unlimited accounts. In this case, having paid hints requiring costs that deduct points may not be a reliable mechanism as users may create throwaway accounts to unlock hints, and then use the hint knowledge on their primary account.
Prerequisite Hints
Hints can optionally have prerequisite hints. For such hints, the contestant should unlock the prerequisite hint before they can unlock the hint. By default, hints do not have prerequisite hints.