Brunei has a totally banned alcohol for it's locals.
Sale of alcohol within Brunei is also not allowed.
Brunei Alcohol Policy for Foreign Tourists
Foreign tourists can bring up to 2 bottles of wine or spirits and 12 cans of beer into Brunei every 48 hours. If you carry alcohol into Brunei you have to declare this information at customs at the time of entry. They'll give you a form to fill at customs, don't lose the form some hotels will ask for it before allowing you to access your hotel room with alcohol.
Legal age for taking alcohol in Brunei- 17 years
Drink from your private residence or hotel room. Being intoxicated in public is a crime.
Other Things To Avoid Doing In Brunei.
Don't overstay your visa, punishment is always harsh ranging from fines, short prison sentences or caning.
Don't celebrate Christmas or put up Christmas decorations openly- Being a strict Muslim country public Christmas celebrations can attract a fine of up to $30000 or a five year jail sentence.
Never say anything negative about the sultan or prince of Brunei while in the country.