Hello friends, thank you for reading my message.
I have a simple question - my friends and I were to get our hands on an old version of YGO Pro (which is up to date with an old format), would it be possible to play that old format online together?

Thanks again.

If you're talking about playing MR3 (Pendulum era), MR2 (Xyz era) or MR1 (Synchro era), you can do that in the Links Beta (online on the servers). If you're talking banlist-wise, just build your decks around an old banlist.

To answer your question, if you get any YGOPro version that's older than 1.033.D (this is the last version before the Links Beta), you won't be able to play online, as there won't be servers compatible with it (you could play in LAN I guess).

Thank you, friend! This was very helpful and I appreciate it!