You've always enjoyed making prank calls. When you were a child, you thought nothing of it. Now that you're an adult, though, you're starting to wonder about the ramifications. Do they go beyond simply annoying the person you're calling? Could you be arrested?
Generally, you're not going to face legal ramifications for an honest joke, but the problem is that you may consider it a joke, while someone else thinks of it very differently. This is what could lead to charges, depending on the nature of the call.
You could face accusations of harassment or disorderly conduct. This may have to do with what you say and how often you call. One prank call to a neighbor likely won't trigger a call to the police. "Prank" calling your ex every day for months on end could lead to harassment accusations.
You could be accused of a hate crime if your prank includes making disparaging remarks based on a person's race, religion, national origin, sexual orientation, gender or something else along those lines. Even if you call it a prank, it may then come off as a verbal assault. If you make any threats, that vastly increases the risk of criminal charges.
Finally, if you record the call, hoping it will be funny and you can post it online later to show your friends, you could then be in violation of wiretapping laws. In the worst cases, you could face felony charges.
As you can see, there are very real legal ramifications to prank calls, even if you thought they were no big deal. If you're facing charges, you must know your legal defense options.
Source: FindLaw, "Can Prank Calls Get You Arrested?," Andrew Lu, accessed Feb. 01, 2018