Conditions races are horse races where the weights carried by the runners are laid down by the conditions attached to the race. Weights are allocated according to; the sex of the runners, with female runners carrying less weight than males; the age of the runners, with younger horses receiving weight from older runners to allow for relative maturity, referred to as weight for age; and quality of runners, with horses that have won certain values of races giving weight to less successful entrants.
Conditions races are distinct from handicap races, where the weights carried are laid down by an official handicapper to equalise the difference in ability between the runners.
Conditions races are staged at all levels of horse racing, as all of the most important races in Europe are conditions races, the term may also refer to the races for the very best horses, which are split into four levels, namely:
- European Pattern Races
- Group 1 (G1) - (Classics and other races of major international importance)
- Group 2 (G2) - (less important international races)
- Group 3 (G3) - (primarily domestic races)
- Listed Races - have less prestige than the group races but are still more important than handicaps.
The pattern system, overseen by the European Pattern Committee, is fluid and the Group status of key races can change. By this method, the Prince of Wales Stakes at Royal Ascot was upgraded from Group 2 to Group 1 in the year 2000. However, a number of checks and balances are in place which ensure that changes to the Pattern are gradual and evolutionary, thereby giving the racing industry time to adjust. In particular, the current European Pattern Committee "Ground Rules" explicitly state that no race may be upgraded by more than one Group in any one year. Such restrictions can prove troublesome when major new races are launched. For example, the Dubai World Cup, the world's richest horse race, was only given Listed status for its inaugural running in 1996.
The pattern system exerts a huge influence on the bloodstock market, particularly in relation to the stud fee that a stallion can command for covering a mare at stud. This will be dictated almost entirely by the stallion's performances in Pattern races during its racing career. Only the very best horses can perform successfully in Group 1 events and such animals invariably command the highest stud fees when their racing career is at an end. A top-quality stallion can be enormously lucrative for its owners - stud fees of more than US$100,000 are relatively commonplace for the most coveted stallions.
In North America, the best horses race in "graded stakes races" instead of "conditions races". The division is similar to that for pattern races in the rest of the world:
- Grade I
- Grade II
- Grade III
In Australia and New Zealand, the best horses race in "Group races" which are decided by the Australian Racing Board and New Zealand Thoroughbred Racing Incorporated respectively. These races are divided into four levels:
- Group 1
- Group 2
- Group 3
- Listed races
Unlike in some other countries, handicap races can be included in the North American and Australian grading system; although most graded stakes race in North America and Group races in Australia are most conditions races, and handicaps are more often seen in races of lower level, there are still several handicaps are Grade I or Group 1 races respectively.
For lists of races go to: