I am currently in Malaysia. Before I left I notified my credit card companies about my travel. Few businesses here accept credit cards and often there's a minimum purchase of RM50 (about $16 USD). I had been buying gas at the pump without incident until last week. All of my cards were declined. I drove on into work. I called one of my card companies. She said they didn't issue the refusal so what probably happened was the gas station's bank wasn't talking to the US banks. Fair enough. That evening I was able to buy gas.
Next time I bought gas the pump said it could only process credit cards with a chip. I was with some local coworkers. I asked what that meant. I showed one of them my card. He laughed and passed it around. They hadn't seen a credit card without a chip. He showed me his and and sure enough, it had a chip. It was unlike anything I've seen on US-issued cards. It wasn't the same as the "touch-n-go" type cards some US banks are issuing. I'm not saying no US bank uses this. I'm just saying I've never seen anything like it.
I went inside and the clerk was equally baffled and said she couldn't accept a card without a chip.
I have no idea why my credit card worked just fine for a month and suddenly is being refused due to lack of a chip.
In short it can be a pain [in] the shorts to use credit cards overseas, particularly in a country known for credit card fraud. I check my accounts every other day. So far, so good.
But cash isn't always the answer either. Since we're in a largely cash-based country, my company offers cash advances. I took them up on it. I deposited the money into my checking account and I use my ATM card to withdrawal cash as needed. My bank doesn't charge a foreign exchange fee and rebates me back any ATM surcharges. I also get the best exchange rate regardless of the amount withdrawn. My coworkers elected to bring US currency with them and exchange at a money changer. Money changers charge a per transaction fixed amount and don't give a very good exchange rate. The official rate is 1 USD = 3.141 MYR. I'm getting right about that while they're getting 3.05 MYR/USD. They're carrying mostly 100 dollar bills and the money changers won't accept certain ranges of serial numbers. One woman is sitting on a pile of cash she can't spend. Personally I'd be nervous about having that much cash on me.
In short I believe using an ATM card to withdrawal local currency is your best bet and rely on credit cards only for hotel stays and car rentals.