The world's top chess federation has ruled that transgender women cannot compete in its official events for females until an assessment of gender change is made by its officials.
The decision by Lausanne, Switzerland-based federation FIDE was published on Monday and has drawn criticism from advocacy groups and supporters of transgender rights.
FIDE said it and its member federations increasingly have received recognition requests from players who identify as transgender, and that the participation of transgender women would depend on an analysis of individual cases that could take up to two years.
"Change of gender is a change that has a significant impact on a player's status and future eligibility to tournaments, therefore it can only be made if there is a relevant proof of the change provided," the federation said.
"In the event that the gender was changed from a male to a female the player has no right to participate in official FIDE events for women until further FIDE's decision is made," it said.
Holders of women's titles who change their genders to male would see those titles "abolished," the federation said, while holding out the possibility of a reinstatement "if the person changes the gender back to a woman."
"If a player has changed the gender from a man into a woman, all the previous titles remain eligible," the federation said.
It acknowledged that such questions regarding transgender players were an "evolving issue for chess" and that "further policy may need to be evolved in the future in line with research evidence."
No one immediately responded to emails to top federation officials and calls to the federation's headquarters in Switzerland seeking further comment.
Word of the decision comes as the federation is hosting a World Cup event in Azerbaijan where top players including No. 1-ranked Grand Master Magnus Carlsen of Norway are attending.
The federation has open competitions that allow all players to take part, as well as specialized categories, such as for women, young players and even computers.
Many sports involving intense physical activity — which chess does not — have been grappling with how to formulate policies toward transgender athletes in recent years.
The International Cycling Union has joined the governing bodies of track and field and swimming as top-tier Olympic sports addressing the issue of transgender athletes and fairness in women's events.
Last month, the cycling federation ruled that female transgender athletes who transitioned after male puberty will no longer be able to compete in women's races.