Domestic and overseas fans will be barred from all Olympic venues in Tokyo and three surrounding regions over virus risks, putting most of the Games behind closed doors.
But a handful of events are taking place outside the capital and nearby areas, with different rules for those areas. Here are the current standards:
In Tokyo and the surrounding prefectures of Chiba, Saitama and Kanagawa, all fans will be barred from all events.
This applies equally to venues from the 68,000-seat National Stadium that will host the opening ceremony and the seaside surfing site in Chiba.
Olympic officials, dignitaries and others deemed "stakeholders" will still be allowed in the stands.
Tokyo will be under a virus state of emergency until August 22, which largely involves limiting alcohol sales and restaurant opening hours.
Most Olympic events will take place in the capital, including key draws like athletics and swimming, but also local favourites karate and judo.
In four prefectures, spectators will be allowed with strict limits.
Fukushima and Miyagi, in northeastern Japan, will host baseball, softball and football matches and allow up to 50 per cent venue capacity or 10,000 people, whichever is less.
The same standard will apply for central Japan's Shizuoka, which is hosting cycling events.
In northern Ibaraki prefecture, also hosting football games, only school children will attend.
Fans will be allowed at evening sessions in Miyagi, but not in Ibaraki.
The biggest event in northern Hokkaido will be the ever-popular marathon. The event was moved to the cooler climes of the island, along with the race-walking, to escape the stifling Tokyo heat.
Organisers have asked people to stay away from the routes of both events, which are not ticketed as they take place on public streets.
The other event in Hokkaido is football, where the limit of 10,000 people or 50 per cent capacity will apply. A decision on attendance at night sessions has not yet been made.
According to organisers, out of 750 competition sessions during the Olympics, spectators will be allowed at just 34, or 4.5 per cent.
A lottery will determine which existing ticketholders can attend those few sessions still open to fans. Results will be announced on Saturday.
The refund period for those unable to attend events will run from June 10 to 20.