How do you check someone's IP address? (I know this is a stupid question >-<)

Why would you need to know this?
Most people don't know each others IP address for privacy and security concerns.

I was just wondering cuz I see on people profiles stuff like "My IP address might be the same as ___ because ___" and I was wondering like, why would they say that if there was no way to check... so I thought there was and I was just wondering....

Oh! People who share IP addresses know this because they live together. I think they put this on their profiles because there is a limited amount of accounts that can be active on one IP address.

ohh ok, that good to know cuz when people put them on profiles I got so confused XD

As Whiterose said, these disclaimers are made to make it clear that there are multiple people playing Sylestia from the same place / IP address. This is to let Krin and Fai know (who, as owners of the site, *can* see that information) that the multiple accounts logged in from the same place are different people and not one person breaking the no multi-accounting rule. Also, there is a max (I think two? Might be three) number of accounts that can share the same IP before having to message Krin to allow more accounts at the same place, which is also an attempt at stopping people from making more than one account.