We will be traveling to Central Europe next month. 3 of the 5 countries we are visiting are not on the euro currency system. We mostly use our credit card for purchases since our CC doesn’t charge foreign transaction fees, plus I rack up points. My question is this.... rather than change to local currency can I use euros? I understand any change given will be in local $.

I'm not sure if I understand the question. If you use a CC, and presumably don't accept any dynamic currency conversion, why would euros come into question in those countries that don't use the euro? I must be missing something.

If you're talking about using euros for cash purchases, yes, you'll definitely lose something on the exchange, and will get change back in the local currency, but why wouldn't you just use an ATM card to get the local currency out of an ATM?

I believe the question is for cash purchases. I haven't been to Budapest in ages, but when I was there, some places did take euros as their currency isn't very convertible (at least it wasn't then). As for the CR, I always use koruna there but think I did see some places with big tourist clientele that accepted euro. As usual, you will probably not get a good exchange rate. In Poland, some places accept euro also in the big cities and that cater to tourists. Watch out for DCC there, I encountered that in Warsaw in particular.

YOu are most likely to be able to use it in souvenir shops and big chain stores in the major cities and restaurants in tourist areas. I mean the dead center of tourist areas where that is most of their clientele and prices are higher.

So yes, I think in some places and some establishments you can, but not all. I don't think you really need to figure this all out ahead of time. When you get there, you'll find out and if it's a burden and you'll be there long, just go to an ATM and get some local cash.

You certainly won't receive "local $" as change because none of these countries has a curreny called dollar...

Use the respective country's official currency if you use cash, and no other. These aren't banana republics with kauri shells as money. Euros might be accepted at some tourist places, certainly not everywhere, but then if they are, at a lousy exchange rate. Why lose money twice?

Two years ago plenty of the schlocky stores in Budapest were happily taking euros. I think some cafés and restaurants were, too. We always got forints from an ATM and paid in cash or used a CC.

Not quite sure why you are asking since you do seem to know what currency each coutry uses.

It is almost always better to use credit cards (charged in the local currency only) - and when cash is required, the local currency (out of an ATM/cash machine)

Don't be using € (or $) in non-€ countries.

It's been our experience over the last six years that Euros (in Hungary and CZ) are becoming less and less accepted in the touristed areas; occasionally we can get by with using Euros if we stop at farmer stands near the borders, but that's about it. And as quokka writes, "why subject yourself to double lousy exchange rates?"

Save your local change to use on last day in the country.
If necessary, buy candy bars. Or leave tips. Better to leave a smile on a face with a tip, than clutter up a dresser drawer back home.

It's perfectly understandable to want to avoid additional money changing or ATM withdrawals for just a small amount of cash usage in countries where you may spend just a short amount of time. Can't fault you for wanting to find ways to avoid this as these transactions and any re-conversions cost money.

But as others have said, using Euro in non-Euro countries will subject you to poor (and let's say 'informal') exchange rates in shops and, worse, overt cheating. Even where Euro is more formally accepted, it adds an additional layer of complexity to every transaction and increases your chance of being cheated, especially in crowded, fast moving places. So anything you might save in avoiding additional money changing is likely to be far overshadowed in additional cost for reasons described. And the reason why you need cash (I assume) is to have some money for where CCs are not accepted or they are just small incidentals. It's likely that many places not accepting CCs will also not take Euros or, more likely, be overtly predatory with the cost in Euro.

Do you seriously believe that OP is expecting to get "Hungarian dollars" or "Czech dollars" in return if OP already knows that the respective countries are not using the euro?

They will have found out in the meantime, since this thread is a year old.