I'd be grateful if anyone had some insight into something that I'm no expert on (networking).

Long story short, me and a few friends get together to play some old Win9x games online (on Windows 10). A good portion of them utilizes DirectPlay (version 6 and older most likely). In order to play most of them online, the process is the same: Open up 3 specific ports (for DirectPlay and the actual game), add an exemption in the firewall for the game's exe, and hand out my IP to the joining players (since I'm usually the host).

It works just fine. But, what if, someone new comes along and wants to play with us, but they have ill intentions? Would my PC be vulnerable because I opened 3 ports (the other person would know the 3 since joining players have to as well), my firewall exempted the game's exe, and they have my IP? Plus, these older games relies on DirectPlay, a feature that's been phased out.

I'm just wondering if there's any steps that we can take to protect ourselves. I thought about using something like Wireshark while hosting a game, and if said person tried to do something, I'd have their IP so that I can quickly block 'em out. But it might be too late if it gets to that point. Then again, maybe it's not really possible for someone to be malicious simply because I opened up a few ports and gave out my IP? I don't know?

I apologize if any of this sounds obvious or too hypothetical, but my knowledge on this topic isn't vast at all. I wanted to expand a few older communities, but I can't do that if there's security issues like this.