[bathory]

I have spent more than 10’000 hours in DotA 2. You do not get banned for a single game no matter how bad you perform.

It has to be on a very regular basis, and even then you probably first get put into low priority matchmaking as your behavior score drops. Banning accounts usually only applies to cheats or buying and selling accounts.

[fxtentacle]

You are technically correct. I got limited into a different matchmaking system than my friends. But the end result was that I couldn't play with them anymore.