I want to make a server. I didn't know my router admin and password, so I asked my mom. She freaked out, and I explained to her I was making a server on a game. She still told me that it was harmful, and hackers could then get in our computer. I needed my router stuff for the program "Simple Port Forwarding". What I'd like to know, is is it really harmful? Will it destroy our computer? It's just a game, for heaven's sakes.
All these answers lack what he asked, no, it is not harmful, unless it is a proffesional X-government hacker, i doubt someone can hack into your computer, or even would want to, through opening a port for a game.