The first World Championship to be held as an individual event was in 1930.
Twelve different nations participated.
Canada's team was given a bye to the gold medal game, and the rest of the nations played an elimination tournament to determine which nation would also play for the gold.

In 1931, the World Championships switched to a similar format to what was used at the Olympics.
Ten teams played series of round-robin format qualifying rounds were played to determine which nations participated in the medal round.
Medals were awarded based on the final standings of the teams in the medal round.
The format was changed several times in the 1930s, in some years there was a gold medal game, while in others the gold medal was awarded based on points.

In 1937, the tournament format was again switched to being similar to the version used at the Olympics.
A preliminary round involving 11 teams was played, then the top four advanced to the medal round and medals were awarded based on points; no gold medal game was played.
A gold medal game was played in 1938; it was the last gold medal game played in the World Championships until 1992.

In 1951, thirteen nations took part and were split into two groups.
The top seven teams (Pool A) played for the World Championship.
The other six (Pool B) played for ranking purposes.
Generally eight teams played in the top-level Championship, although the number varied over the years, going as low as three (in 1953) and as high as twelve (in 1959).
The same format was used until 1992.
The format was criticized because often the gold medal winner was decided before the final game was played, such as at the 1988 Winter Olympics.

During a congress in 1990, the IIHF introduced a playoff system.

As the IIHF grew, more teams began to participate at the World Championships, so more pools were introduced.
Pool C games were first played in 1961 and Pool D was introduced in 1987.
In 2001, the pools were renamed: Pool B became Division I, Pool C became Division II and Pool D became Division III.
The first World Championship to be held as an individual event was in 1930. Twelve different nations participated. Canada's team was given a bye to the gold medal game, and the rest of the nations played an elimination tournament to determine which nation would also play for the gold.
In 1931, the World Championships switched to a similar format to what was used at the Olympics. Ten teams played series of round-robin format qualifying rounds were played to determine which nations participated in the medal round. Medals were awarded based on the final standings of the teams in the medal round. The format was changed several times in the 1930s, in some years there was a gold medal game, while in others the gold medal was awarded based on points.
In 1937, the tournament format was again switched to being similar to the version used at the Olympics. A preliminary round involving 11 teams was played, then the top four advanced to the medal round and medals were awarded based on points; no gold medal game was played. A gold medal game was played in 1938; it was the last gold medal game played in the World Championships until 1992.
In 1951, thirteen nations took part and were split into two groups. The top seven teams (Pool A) played for the World Championship. The other six (Pool B) played for ranking purposes. Generally eight teams played in the top-level Championship, although the number varied over the years, going as low as three (in 1953) and as high as twelve (in 1959). The same format was used until 1992. The format was criticized because often the gold medal winner was decided before the final game was played, such as at the 1988 Winter Olympics.
During a congress in 1990, the IIHF introduced a playoff system.
As the IIHF grew, more teams began to participate at the World Championships, so more pools were introduced. Pool C games were first played in 1961 and Pool D was introduced in 1987. In 2001, the pools were renamed: Pool B became Division I, Pool C became Division II and Pool D became Division III.
Ice Hockey World Championships