Is scamming illegal?

First of all, I'm not about to scare anyone, do not worry. I'm just asking for interest. Can I be prosecuted by the police if, for example, I deprive a boy of his Fortnite Account etc?

This counts as a stolen goods and theft or trick fraud (depending on the procedure) and yes, this is punishable.

Fraud and theft are punishable, even for such Lapalien as Internet accounts.

Sure, that's theft only in the digital version.