Is at&t internet 100 plan enough for gaming?

There are accounts gaming with internet 10

How many people with how many devices doing what at the same time compared to the requirements of the game.

A chess game from lichess.com has no issue on internet 3.

Distance from server, routing of path will affect latency as well as the server itself.

ATT internet 100 is better than 65% of ATT addresses can receive... 75, 50, 45, 25, 24, 18, 12, 10, 6, 5, 3, 1.5 and .76 are the speed tiers offered below 100 while direct fiber speeds above 100 are 300, 500, 1000, 2000, 5000. 

Yes.  That’s what I use.  

I have good ping on 38 mbps so 100 should be good enough