Forewarned is forearmed
In many places you're visiting, you are relatively rich. This makes you a target.
Usually they'll be targeting your money by the easiest means possible - distraction or confusing you into handing it over willingly - and thankfully violence against you is usually unprofitable and thus rare.
You can minimise your risk by not making yourself an obvious target. Avoid appearing wealthy - don't wear visible jewellery or carry expensive cameras and electronics on show. Be streetwise. Don't openly get your wallet out or wave amounts of money around. Don't visit cash machines alone or after dark. Try to wear ordinary clothing which makes you blend in with the locals as much as possible. And avoid standing checking your map - this marks you out as a tourist.
If you are drunk, you make yourself more vulnerable. When going out drinking, take only what you need and are likely to spend that evening, leaving everything else somewhere secure at your accommodation.
Pickpocketing and distraction theft are probably the most common danger. You can minimise how much they get, by splitting your money and only carrying what's necessary, and you can be aware of types of distractions used so that you make yourself less easily fooled.
Distraction theft usually involves someone approaching you on some pretext, and an accomplice stealing from you. This may be a staged disagreement, a crying child, a person begging, a faked emergency, or someone attractive making a pass at you. Be wary of distractions, and have your money and valuables somewhere concealed and hard to access. Avoid keeping your wallet in the back pocket of your trousers - keep a small amount of money to access readily in you pocket, and the rest zipped away in an inside pocket.
As well as your cash, they could be after your passport or bank cards. Scams range from unsophisticated attempts to get your cash just after you've left the cash machine, to skimming or cloning your credit card. Your identity documents are also valuable to them, and a pain for you to replace.
Their easiest way to get your money is if you hand it over willingly. So beware - if an offer seems too good to be true, it probably is. Getting you to buy something at an inflated price, or forcing themselves upon you as a guide who'll then expect payment, are common - another variation is a local giving you a small gift then once you've accepted it demanding payment and not going away till you give them money. Locals in fancy costumes may pose for your photo then loudly try to embarrass you into paying them. And fake officials, or corrupt but genuine officials, may demand bribes or fines for imaginary mistakes with your documentation.
It's a creative old world out there. There will always be new innovations to these ways to fleece you. Google "scams on travellers" before you travel, to remind and prepare yourself.