Groups of four people from different households will be allowed to meet indoors at pubs, cafes and restaurants after Wales' firebreak lockdown ends.
The sale of alcohol after 22:00 GMT will still be banned when new regulations come in on 9 November.
Pubs and restaurants will reopen at the end of the lockdown, but the terms for their operation had been unclear.
Larger groups of people who all live in the same house will be allowed to eat and drink out together.
First Minister Mark Drakeford asked people visit such places in the smallest groups possible.
The rule of four will also apply when meeting people from different households outdoors, away from your home, but meeting anyone from outside your household bubble in someone's garden is not allowed.
Two households are allowed to form a bubble after the end of the firebreak - but groups of more than four people who are in the same bubble will not be allowed in pubs, cafes or restaurants.
Mr Drakeford said reopening would be "subject to strict protections discussed with the hospitality sector, including advance booking, time-limited slots and verified identification".
"Our clear advice to people in Wales is that we should visit these places in as small a groups as possible and, for many, this will only be the people we live with," Mr Drakeford told the Welsh Parliament.
"But we have listened to those young people, and single people especially have told us how important it is for them to meet some friends and other family members."
Since 23 October, hospitality businesses have been closed in Wales for the 17-day shutdown, aimed at reducing the number of coronavirus cases and easing pressure on the NHS.
Public Health Wales has warned about the transmission of coronavirus in pubs and restaurants.
Dr Giri Shankar said: "At the moment there still is a concern about ongoing community transmission - and not just pubs but all of the hospitality premises are high risk - where such interactions happen are a continuing concern."
In the Senedd, Mr Drakeford said the regulations would allow "groups of up to four individuals to meet in a regulated setting such as a restaurant, cafe or pub".
Children under 11 will not count.
Organised activities, where 15 people can meet indoors or 30 outdoors, will not be able to involve selling or drinking alcohol.
There will be a separate exception for up to 15 people to attend a reception for a wedding, civil partnership or a funeral wake, but this will need to involve a sit-down meal.
Prior to the firebreak most people in Wales living in local lockdown areas were only able to meet their own household in a pub.
'Verified identification' concerns
Alistair Darby, chief executive of Wales' largest brewer Brains, welcomed the relaxation of the single household rule but raised concerns about the "verified identification" of customers.
He said it was not clear what it meant as there are no ID cards and the scheme could result in "frustration and irritation" towards staff.
Mr Darby added that the company supported test and trace, but would be worried that verification could lead to conflict between staff and customers.
It will be illegal to provide false information to contact tracers from Monday - it is understood the requirement for verified identification is part of the same process.
Meanwhile, Newport's Celtic Manor Resort Hotel will not reopen until after the lockdown in England ends on 3 December, its chief executive has said.
Ian Edwards said it couldn't "attract enough visitors to make its operation viable" after the UK government's decision on England at the weekend.
What have opposition parties said?
Andrew RT Davies, Welsh Conservative health spokesman, said his party "of course welcome this partial relaxation of rules on visiting pubs, and the wider hospitality sector. We recognise, too, that all people in Wales have a legal and a moral duty to abide by rules set.
"And yet, we again call for any rules, any restrictions, to be proportionate, time-limited, and based on transparent and published data."
Plaid Cymru's economy spokeswoman, Helen Mary Jones, said: "Businesses will be glad that they can reopen but the Welsh Government needs to issue the detailed guidance quickly so that they know in detail what is expected of them.
"There will still be some businesses that cannot open safely or profitably. Government needs to provide targeted long-term support for the businesses that need it most. We have to move on from the broad brush, first-come first-served approach to business support."