Organized interscholastic ChGK leagues exist in 3 countries: Belarus, Russia and Ukraine. In all 3 countries, interscholastic ChGK divisions are divided by grade brackets: 5-7 grades, 8-9 grades, 10-11 grades and university.

The regular interscholastic ChGK season typically features 7 monthly tournaments, from September to March.

A typical Russian school playing in an interscholastic ChGK league will field a single team across the grade bracket. Players are usually among the top students in the grade bracket.

As a result, especially in the 10-11 grades bracket, the majority of the teams will lose several players for either the second or third tournament. It happens because several players will focus on subject olympiads over intellectual games while the city/raion olympiad season is underway. (The city/raion-level stage is the first level of subject olympiads).

For this reason, qualifying for the postseason in secondary school brackets is based on the results from the best 5 tournaments. Top 3 teams from each region, which don't necessarily overlap with the subnational divisions, earn a berth for the national championship.

In Belarus, each grade bracket holds its own national championship separately. However, in Russia, all grade brackets take part on the same dates.

Each grade bracket's intellectual games national championship features several intellectual games spread over two days.

Finally, the Youth World Cup is a synchronous international league for secondary institutions.