Skaters are entered in the individual events either by being seeded or by invitation. The seeding of top skaters at Grand Prix events basically takes into account their placement from the previous World Championships, as well as their ISU international ranking. Skaters who are not seeded can be invited by the hosting country and each country can invite up to three of their own skaters for each discipline. This is to give a balanced field throughout the series, as well as allowing the hosting country a chance to showcase their top competitors.