Often there is situation that a designer does not want to happen. In almost all cases, players are either prevented to create this situation, or are punished for doing so.

An example of a restriction would be in Smash Up, you always discard down to 10 cards at the end of the turn. (restrict you from having more than 10 cards)

An example of punishing would be in Settlers of Catan, you can hold as many cards as you like, but if yo have more than 7, you have 1/6 chance of losing half of them each turn. (punish you for having more than 7 cards)

Which method do you generally prefer?

Can you think of games that would be better off using the other method?