Do credit cards have to have interest rates below usury levels?

Factual Questions
1

Or can they charge whatever APR they want? I’ve heard there are usury levels, but that was just a blurb in an article once.

If they must have APR levels below usury levels, what is the national maximum APR (in the US)? If there isn’t a national maximum APR and it varies by state then what is Indiana’s maximum?

If there is a maximum, are there ways they can get around it so they can charge usury rates but not break the law?

2

Most legislature against usurous levels of interest was done away with about twenty years ago.

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