Usage patterns
損な役回りa thankless or unfavorable role
He always gets stuck with the thankless role.
〈人〉に役回りが回ってくるfor a (usually undesirable) role to fall to someone
This time, that difficult role fell to me.
役回りを引き受けるto take on a role or assignment
He quietly took on the unpleasant role.
役回りを演じるto play (a particular) role
She played the difficult role of negotiator.