When to bet big when counting cards? You should increase the size of the bet when the true count is +2 or higher. This means that there are more cards worth 10 and 11 points in the deck, which can lead to more winning hands.
Technically and legally, playing for any stakes, even inconsequential amounts, is likely to be considered gambling, but playing for money is relatively harmless provided the stakes are well within what the players can afford to lose.