From the introduction:
Proxy is a tabletop game of ‘deep politics’, pitting 4-6 players indirectly against each other as foreign officials trying to secure the continued ascendancy of their realms. The theater that the players are influencing is the civil war of the Kingdom of Gauttland, a regional power that has collapsed into a confused internal struggle. One player will take the role of Conflict Overseer, a game master like role that will see them control all internal factions of the civil war, adjudicate the rules of the game and also manage their own hidden agendas.
The rest of the group will take on roles as representatives of Gauttland’s neighbors and rivals, each attempting to secure their own nation’s political interests in the conflict. The players can influence the factions of the civil war with monetary aid, arms deals, supply relief and espionage; but they have limited control over what the various factions choose to do with that aid. The players can also infiltrate and disrupt the goings-on to whatever degree they like, or if they feel it is in their best interest, make formal alliances with one of the factions vying for power and bolster them exclusively.
The thing is this: there is no one way to win. At game’s start, every player receives their own specific objectives to accomplish in order to win the game, which they keep secret from all the other players. Even the Overseer can get a secret objective. There are also very few rules governing diplomacy and loyalty. Who you trust at the table and who you choose to betray is your decision alone. Every person at the table is competing with everyone else; you just can’t know exactly for what. Statecraft is a dangerous enterprise, after all.