If your bank sends you a new debit or credit card ahead of schedule, you’re not alone. Banks and retail stores are shifting the way they honor plastic, in the wake of a big consumer lawsuit last year. Dan Kramer with Shazam, a regional A-T-M network, explains it stems from an “honor-all-cards” rule. Consumers have the right to go into any store and either sign for their card purchase, or punch in the Personal Identification Number, their confidential PIN, but he says “signature-based” deals have higher risk because they’re more prone to fraud. Kramer says it turns out all cards are not created equal. He says PIN-based cards have less risk and, as a result, fees for signature-based transactions were a lot higher for merchants — so they sued, for the right to throw out the accept-all-cards rule and control whether they’ll accept signature or pin-based card purchases. One of the biggest names in retail business helped nudge the change. Wal-Mart announced about two months ago it wouldn’t accept MasterCard signature purchases any more, so anyone who uses a MasterCard to buy goods at Wal-Mart has to use a PIN. You may not notice any difference next time you use plastic instead of a check or cash. And Kramer says many card issuers are offering incentives, like bonus plans to customers who use a PIN instead of signing for the card purchase, to make it more attractive to punch in those numbers.