Racism is acceptable in Maycomb, but gambling is not.
When Jem is caught without his pants, he tells Atticus and the other adults that he is playing strip poker. We learn that gambling among kid is not acceptable. Church is “Maycomb's principal recreation.”
I admired my brother. Matches were dangerous, but cards were fatal. (ch 6)
Although some white men gamble in the black church on weekdays, most of the people in the town don't seem to approve of gambling in general.
However, most of the town accepts racism. It is quite common to consider blacks second-class citizens, and to treat them badly just because of the color of their skin. It is acceptable for a jury to convict a black man for no other reason than that a white woman accused him.
"You did all this chopping and work from sheer goodness, boy?"
"Tried to help her, I says."
Mr. Gilmer smiled grimly at the jury. "You're a mighty good
fellow, it seems- did all this for not one penny?" (ch 19)
Gilmer calling Tom "boy" upsets Dill so much that he has to leave the courtroom. He can't stand the institutionalized racism that he sees in the court. But it is acceptable to others.