Where to hide your money in high-risk areas?

In my opinion, trying to get out of an armed robbery for less than $100 US equivalent or so is a lot of risk of harm for an utterly negligible amount of money in the greater scheme of things. So plan for a minimum amount in your pocket after all expenses for the outing. You don't want a desperate and violent criminal armed with a lethal weapon and pumped up with adrenaline and/or drugs to be enraged at you.

In cases where I take a certain calculated risk- say going to a market known to have a lot of scams and outright thefts, then I would leave almost everything in a hotel room safe, even some cash. I would keep money in more than one place on my person so I would still have enough money to get back 'home'. Do the minimum with respect to ID that you can in the country (in some places it's illegal to wander around as a foreigner without a passport, and in some of those places it might actually be taken seriously). ATM cards where you could be forced to withdraw large amounts of money are risky- in places where that sort of thing happens you can not carry them, or have the maximum amount you can withdraw per day reduced to something tolerable. Or find insurance that would cover it. A credit card such as Amex is probably safer.

If you are going to be doing things that go past 'risky' into the illegal arena such black market money changing, illicit drugs, prostitution and such like you are taking a much bigger risk since you will definitely be dealing with criminals and they have an excuse to get you into a private place. I suppose a money belt would help unless your evening's plans include disrobing completely. Best not to.

Although I have yet to be robbed or attempted to be robbed by any method but stealth or intimidation, I do try to have sufficient resources available that, were I to awaken naked in a ditch, I would still be able to get on a flight home without too much additional trauma. Electronic copies (or photocopies in the old days) of all important documents, card numbers and bank phone numbers, some cash, perhaps in an inconvenient currency for example.