How the roles interact: who knows what
This page explains the asymmetry of information: it is what creates strategy and deception.
Civilian ↔ civilian
They do not reliably know each other's roles. Matching versions do not mean a shared team; differing ones do not mean that one of them is mafia.
Civilian ↔ mafioso
A civilian sees only public actions. A mafioso knows that they are not the city, but does not know the affiliation of most of the others. So even true accusations by a mafioso can serve the goal of another team.
Irish ↔ Italians
These are opponents who do not recognise each other automatically. They may by chance defend, accuse or jointly attack the same person. A temporary match of interests does not make them allies.
Sheriff ↔ both gangs
The Sheriff learns the exact side of the checked player. The bosses can find only the Sheriff, and do not get a mirror list of roles. A reveal of the Sheriff can harm both gangs at once.
Boss ↔ Gangster; Don ↔ Mafioso
Inside each pair the partner's affiliation is known for certain. At the same time any public coordination carries the risk of exposure, and the rules for allowed night communication are set by the Sport Mafia rulebook.
The table ↔ a claim about a role
A public "I am the Sheriff" is a player's statement, not a confirmation by the host. The check is true for the real Sheriff, but retelling it in public can be challenged or faked by a rival.
The paradox of a successful accusation
If no. 4 convincingly proves that no. 7 is a mafioso, no. 4 may turn out to be a civilian, the Sheriff or a member of the other gang. A successful accusation is information about no. 7, not an automatic acquittal of no. 4.