Knowing how to improving your credit score used to be an act of faith. The consumer would pay their bills on time, keep their debt to a minimum, and hope this type of good behavior would be the right mix to earn a FICO score of 750.

Thanks to FICO’s decision to give full disclosure, knowing what behavior improves your score is now an exact science. Below are the damages and how they affect your FICO.

Maxed-out credit card. If your score is around 680 or touching below average, you can expect a dip of 10 to 30 points. Thanks to the new Credit CARD Act, you can opt for any purchase that will put you over the limit to be declined on the spot. Roughly 30% of your FICO is about how much you owe, so keep it to 25% of less than what you can spend.

30-days late on payment. This serves as a big sign to creditors you are getting in over your head. In response, if you had an excellent FICO of 780, your overall score can drop a full 110 points upon just one reporting of being late. About 35% of your score is based on payment history.

Entering debt settlement. Another ouch for FICO scores of any size, with scores dropping from 45 to 125 points. Don’t believe what debt settlers tell you about your credit not taking a hit if you sign up for this type of service. Attempt to negotiate the debt down yourself, which doesn’t take a hit on your score.

Foreclosure. One of the worst and longest-lasting credit hits takes as high as 160 points off your FICO. Take advantage of the government-sponsored Home Affordable Modification Programs or enter a short sale.

Bankruptcy. The mother of all negative credit marks, a score of 780 can drop to 540 once the paperwork is filed. Bankruptcy is rarely the right answer and doesn’t wipe your financial slate clean. In many circumstances, you are still obligated to pay back your debts.