how do i convince my parents to let me use their credit card to subscribe?

I would be paying them cash for the subscription.

Step 1: do all your chores.
Step 2: complete all homework.
Step 3: hand them the cash with a description of what it is for.
Step 4: play vendetta happily.

that is how things went down in my youth when i needed a credit card... well except for Step 4.

cool! i'll try it out!

You can actually subscribe with cash, using PayByCash, I think.

As someone in a similar situation, I thought about PayByCash too... then I realized the extra $3 a month wasn't worth it. Just convince your parents :)