I got a question from Cris asking about how the characters in Animal Crossing "read" the letters that you send them and come up with a response. Specifically, what's required for a good response with a gift? I've also been curious about this, so I took a look at how it works... As soon as you drop off a letter at the post office it's given a score. The score is determined by a series of 7 different checks, labeled A through G.