Diplomacy

Diplomacy runs monthly and governs how nations relate to one another: who is allied, who is a rival, who may attack whom, and who counts as a great power.

Relations#

Any two nations have exactly one relation, which is one of:

• Alliance — lasts 10 years.
• Guarantee — a promise to defend.
• Truce — lasts 5 years, and blocks war between the two parties.
• Rivalry — declared hostility.
• Neutral — the default.

Alongside the relation kind, every pair has an opinion value that drifts over time in response to what each side does.

Rivalries cost 12 diplomatic points to declare and a nation may hold at most 4. Rivalry is a scarce, deliberate choice, not a mood.

Casus belli and infamy#

You cannot simply declare war. You need a casus belli — a specific, recognised justification, which lasts 2 years once acquired. Each war goal type has its own rules about when it may be used and what it costs.

Fabricating and pressing claims generates infamy, and infamy has a hard limit of 18. A nation that pushes past it becomes a target for everyone else. Infamy is the main brake on serial aggression.

Two categories of war goal are discounted because the world finds them more legitimate:

• Irredentist claims — taking land inhabited by your own people — cost 45% less infamy.
• Unification claims cost 60% less.

This is a deliberate historical shape: the nineteenth century tolerated nation-building in a way it did not tolerate naked conquest.

Great powers and spheres#

The top 8 nations by power score are the great powers, ranked 1 to 8. The ranking is recomputed as power shifts, and losing great-power status has immediate consequences: a nation that drops out loses its entire sphere of influence at once.

Great powers draw smaller nations into their sphere. Only non-great-powers can be sphered — one great power cannot sphere another. If your patron falls out of the top 8, you are released automatically.

What this means in play#

• Acquire a casus belli before you want the war. Two years is a comfortable window; nothing is a very short one.
• Watch your infamy. The limit of 18 is the difference between an expanding power and a pariah everyone has a reason to attack.
• Unify rather than conquer where you can. The infamy discount on unification and irredentist goals is large enough to change which wars are affordable.
• Truces are 5 years long. Signing one closes that front for a long time. Take it into account before accepting.
• Rivalries are a budget. Four is the cap. Choose enemies you intend to fight.
• Sphere membership is contingent. Your patron's rank can collapse and take your protection with it.

See also#

• War — what happens once a casus belli is pressed
• Crises and the Concert of Europe — how great-power tension becomes a war nobody individually chose
• AI nations — how everyone else makes these same decisions