ATM cards are a very convenient way of accessing cash while overseas. There are a few things though that you should be aware of to avoid or at least minimise problems. Some of these have been learnt from experience. You definately want to be enjoying your holiday rather than spending time in banks trying to get your card back.
Before you go
Make sure it is an internationally recognised card (Visa / Mastercard / Cirrus etc). Not much good having a local card that isn't widely recognised. It is also a good idea to ensure that the ATMs in the resort are affiliated with the network to which your financial institution belongs. For a small resort with not many ATMs this can be a problem.
Make sure that your PIN is 4 digits. Some cards allow PINs of up to 7 digits, however there are many ATM's that will only accept a PIN of up to 4 digits, so clearly this won't work.
Make sure you know or can derive your PIN in numeric format. Using an alphabetic version can make your PIN easier to remember, but there are some places (eg. in Seoul) where there are no letters on the keypad. To make it worse the numbers are sometimes also arranged in a different way. Also the alpha to numeric key mappings on different machines and phones are similar but not always exactly the same.
Make sure you have alternatives. Always have some cash for when you can't get to a machine, the network is down, you've lost your card etc. Have cash in the local currency, US dollars or Euro. In Japan you will need to use cash predominately anyway. Also have a credit card (if your ATM card isn't already one).
Be aware of the bank charges for use of ATMs.
Keep a record of your card numbers and also your bank contact details in a place away from your card or maybe with someone at home. If you do somehow lose your card it is a bit easier to get it back or at least have it cancelled. If you have more than one card, keep them separate. If you lose one and have to cancel it you can use the other, and use Internet or telephone banking to move funds between accounts. Of course you should be very wary when you access bank accounts from public computers. It should only be done if there are no other options available.
Many banks now offer debit Visa or Mastercard cards. These give access to cash in appropriate machines without incurring cash advance interest rates. They can also be used for purchases in shops, restaurants etc.
Look for international ATMs. They will normally display symbols of the various cards they will accept. There will be a logo somewhere on your card that matches a logo on the machine. If you have a denit Visa or Mastercard you can access cash from machines with these logos as well. In various parts of Europe they will be known as Bankomats.
Look for machines that operate as a swipe or dip rather than inserting the card into the machine for the whole transaction. Swipe machines cannot refuse to disgorge the card.
Make fewer larger withdrawals rather than many small ones. This will depend on the bank charges, but often they will be a combination of a percentage of the withdrawal plus a fixed fee per withdrawal, so more withdrawals will mean more charges.
ATM account types are often references to the location of the keys on the machine, not the name of the account displayed on the machine screen. If you select the type of account using the middle button on the machine at home try using the middle button on the foreign machine, regardless of the account description. Or the top or bottom. If a machine is not disgorging money try the other available buttons. But be a bit circumspect - some machines will take your card hostage if you have too many failed withdrawal attempts. See the paragraph above about swiping or dipping.