I assume you want to visit Vietnam and is worried about certain scams you might encounter. I can’t tell you all of the common scams in Vietnam but I can tell you the most popular scam in Vietnam which as a foreigner, you should learn about.
Foreigner tax: Since the differences in exchange rates between other countries to Vietnam makes it so that currency from EU, US, UK, AU, JP… Basically, currencies from developed countries are really valuable when exchanged to Vietnam Dong (Vietnamese currency). a result of this is a foreigner buy much more when he or she comes to Vietnam, so Vietnamese seller has a way to take advantage of this which is by raising the original price of items or services up to 50% and foreigner can’t even tell the difference. Shops with pre-printed prices don’t do this since it is technically illegal for them to do this while shops that don’t have pre-printed prices, flexible prices can do this and it is legal for them to do that if you agree to the price. There are not a lot of ways that you can counter this actually, but one thing you could do is to only go to places where the prices are fixed or pay a little bit more to have the full Vietnamese experience since currency exchange rates make it that so that foreigner tax doesn’t affect you that much, most of the time you would not even realize it, the real problems happen when the prices are raised to 200%-400%.
Thievery: When the prices are raised to more than 200%, this is bullshit and is basically a scam. But the thing is you have to remember, the price of an item can be whatever you agree to pay, so the laws have no leash on these kinds of scam. My tips to prevent this are:
With these tips, I can guarantee you that you won’t be affected by these kinds of scam at all and these are the scams are the likeliest scams in Vietnam you will encounter as a tourist so good for you mate.