How often can one open credit cards without affecting your credit score?

LadyMar asked:


I have been using rewards cards and paying off the balance for years. I have read that applying for new credit card wont affect your record if you only get one, and don’t open too many in a short period of time. Not sure what “short period of time” is . There are 3 rewards cards I have been meaning to get because of bonus/rewards, but not sure how I should space them out.

http://creditcardsandchecks.com