I've heard from a few sources that generally you can't purchase chips at the cashier/cage - that you have to buy your chips at a gaming table. Is this the exception or the rule?

Why would a casino care where you bought your chips? Are you required to play at least one hand/roll at the table where you buy your chips? Do they figure they have a better shot at your money if you're having to buy them at a table and thus feel obligated to play a hand or two at it?

Is it bad form (or even against the house rules) to buy chips at a table without even playing a hand?

If you haven't guessed, I've yet to buy chips at a casino (but I hope to later this week!).