I've been dismissed by my company (mostly by one person in that company). Now I got a new job offer but the manager in question is one of my referrals. How much am I screwed?

Guess it depends on why you were dismissed.

Depending on where you're located your previous employer could open themselves for a lawsuit if they cost you a job if they provide opinionated information without property documentation.

For instance they can say: " he was a hard worker but rarely listened to direction."

But they cannot say: " he was lazy and never worked."

Were you dismissed for "Gross misconduct"? If so, you're attached to another object by an inclined plane wrapped helically around an axis. You're screwed.

Otherwise, it'll just be a neutral reference. If you've "failed probation", it's not likely to be a big deal, just make sure you have an explanation. If you weren't there very long and you've got other positive references, it should be OK. If you were there several years, it could raise eyebrows. If you get on with your colleagues, you can suggest them instead.

Contract is now signed.
Basically I've been dismissed after my prob mainly for a lack of communication but it feels a bit like another random shoot of my manager (I am not the first one anyway) in a company that was a bit complicated. I am not resentful because I was about to resign, but obviously I made the mistake to not talk about it during the interview, made me feel a bit anxious but everything seems to be fine. Thank you for your answers!

@Tounai PAAARRRRTTTTYYYYY!

I must've misunderstood but... Sounds like you're saying you applied for a new job while you still had your old one. Then your old manager fired you for lacking communication. Now this same manager is the reference you gave when applying for your new job?

And you did not mention this during the interview so now they could call your old manager at any time?

@jiraTicket yep kind of