Challenges are a NationStates minigame, added on November 12th 2012, the ten year anniversary of the site's founding. The page dedicated to this original event and its announcement message is still publicly available on NationStates. The minigame allows you to select another nation on the site, and challenge them according to the only variables that the game is able to comprehend: Stats. This page can be reached by travelling to the page of the nation you wish to challenge and pressing the targetting reticle, or by navigating directly to the Challenges homepage.
Success within this minigame provides no additional effects or perks for your nation, and records of your gameplay are only visible inside the challenges game, itself. If a nation CTEs, its levels and progress within the Challenge Ladder will be erased. Therefore, as with everything, if a player wishes to keep their standing in the game, remaining alive is the most effective strategy.
Each competition against another nation is broken into rounds. For evenly matched players, there will be five rounds. In each, census stats will be chosen at random and compared between two nations. Whichever nation has the highest value in the randomly selected census stat (even if both players are in the negative) wins the round, and whichever nation wins the majority of rounds will win the challenge. Competitions for all evenly-levelled nations are therefore effectively decided by how many issues a nation has answered, how consistently they responded, and how old a nation is. It is possible for a challenger to tie with an opponent, if the exact stat value is the same.
The minigame features a levelling system which gives substantial advantages in the competition. A nation's starting level is determined by the number of world census stat badges that a nation has on their main page. Only the volume of badges determine the level, and the quality of the badges (whether they are top 1%, 5%, or 10%) has no impact. Regional rank badges also have no impact.
In addition to the levels granted by census badges, a nation can level up through championship points. Levels generated in this manner are awarded according to table conveniently located on the right sidebar.
A match between evenly-levelled opponents will take place across five rounds. For all unevenly matched opponents, the nation with the higher level will start with a point advantage equal to the number of levels they have over their opponent. A level 5 nation must then win one extra round against a level 6 opponent than they would have to if both nations were the same level. Additional rounds will be provided for nations who have greater than a five level discrepancy between levels, but they must win all of the rounds. If it is no longer possible to win the match, the remainder of the rounds are skipped.
As it is extraordinarily difficult to challenge a nation which is a grossly higher level, a matchmaking system exists to compete against nations within a level or two of your own.
Championship Points are awarded to nations who successfully defeat other nations in a Challenge competition. Their base value is the level of the target nation. A +2 modifier is added if the target nation happens to reside in the same region as the challenger. Those base points are then modified by the circumstance by which the competition was won. If it was the first time defeating the nation, if it was a new record for the challenger, or if the challenger lost no rounds, the points are multiplied by two for each circumstance. If the opponent was a lower level than the challenger, the points are cut in half.
Because the amount of points necessary to advance scales so rapidly, after a certain point, it becomes easier for a nation to try to generate a new census badge on their nation page instead of grinding for more championship points. However, points are, by contrast, not able to be destroyed after selecting a very bad answer on an issue.
Championship points are only awarded to nations who win challenges they initiate. No points are awarded to nations who win challenges issued against them and, due to a bug in the competition graph, may not even be aware that a challenge from a foreign nation ever occurred. There is no penalty for leaving matches which have begun, but where it is highly apparent the challenger would lose.