This page covers inter-alliance diplomacy — the contracts and structures that bind groups of players together (or pull them apart). For one-to-one player diplomacy, see player interaction.
Each alliance has a Diplomatic Capacity stat (Phase 2 asset) that gates how many active inter-alliance contracts it can hold. Capacity grows from:
An Embassy is a building constructed in your capital that opens diplomatic channels to a specific other alliance. Each embassy:
Embassies are mutual — both sides build them, both gain bonuses.
Ambassadors are heroes assigned to diplomatic posts. They:
A skilled Ambassador in a long-running embassy is a major strategic asset — losing one resets bilateral trust.
Contracts go through five states:
Costs are paid up front by the proposer; counter-offers can shift cost.
| # | Contract | What it does |
|---|---|---|
| 1 | Non-Aggression Pact (NAA) | Both alliances cannot attack each other's units or cities. |
| 2 | Mutual Defense Pact (MDP) | If one is attacked, the other auto-joins the war. |
| 3 | Open Borders | Units of either side may pass through territory without penalty. |
| 4 | Trade Treaty | Reduced fees on alliance-to-alliance trade routes. |
| 5 | Faith Tolerance | Missionary attacks between sides cost more, less effective. |
| 6 | Tech Exchange | Selected tech-tree branches share research progress. |
| 7 | Cultural Exchange | Shared culture-flag bonuses in border regions. |
| 8 | Manpower Lease | One alliance lends manpower (in unit form) for fixed duration. |
| 9 | Resource Subscription | Recurring resource shipment at fixed rate. |
| 10 | Joint Wonder | Both alliances co-fund a wonder; joint completion bonus. |
| 11 | Concordance Charter | The peace-victory binding contract — see below. |
Each contract has default duration, breach penalty, and reputation effect. See diplomacy_system.md §6 for the full canonical table.
Contracts are server-enforced where possible (NAA literally prevents the attack action). Soft contracts (Faith Tolerance, Trade Treaty) apply modifiers; breaching them is mechanically possible but flags the breacher and triggers reputation loss.
Reputation is a per-alliance score affecting:
Breaches are heavy reputation hits and persist for a long cool-down.
In Phase 2, a bilateral diplomat layer adds finer-grained, one-time diplomatic moves:
The Concordance is a super-structure: a multi-alliance peace-binding charter signed by ≥3 alliances. When the Concordance covers ≥60% of active players, the Peace Victory timer starts.
The Concordance has internal mechanics:
Breaking the Concordance is the most reputation-expensive action in the game. Most players who try a "false peace" lose more than they gain.
Win condition triggered by Concordance + 60% active-player coverage + 3+ alliance signatories + hold timer. See victory conditions.
Each culture has a unique "envoy" archetype (Sun Dune Caravanserai diplomat, Jade Lotus Tea-Court envoy, Cairnveil Druid emissary). Envoys boost Diplomatic Capacity and grant culture-specific contract discounts.
Sources: diplomacy_system.md, alliance.md, player_interaction.md §3, victory_conditions.md §7.