Classic rules at a glance

This guide introduces the standard board. The adjudication engine implements the detailed rules, including support cutting, retreats, split coasts, and convoy interactions.

Strength and movement

Each unit has strength one. Valid support adds strength to a hold or move. A move into an occupied province must overcome its defense; equally strong competing moves normally bounce. You cannot dislodge your own unit, even with another power's help.

Support

A supporting unit must be able to move to the province it supports into. Most attacks on the supporting unit cut its support, with exceptions involving attacks from the province against which support is directed. A dislodged unit cannot provide effective support.

Fleets and convoys

Fleets can move between adjacent seas and along compatible coasts. Spain, St. Petersburg, and Bulgaria have distinct coasts. Armies cross water by convoy through cooperating fleets at sea. A disrupted convoy may prevent the army's movement.

Retreats

A dislodged unit retreats to a permitted adjacent province or disbands. It cannot retreat to an occupied province, the attacker's origin, or a province left vacant by a standoff. Two units retreating to the same province are both disbanded.

Winter adjustments

After fall retreats, supply-center ownership determines unit allowance. Build eligible units in vacant home centers you still own, up to your allowance. Remove excess units when you own fewer centers than units. You may waive available builds.

Adjudication choices

An explicit VIA order requires a matching surviving convoy and never falls back to a land move. Circular convoy paradoxes use the Szykman policy. Units with no possible retreat are automatically disbanded if no retreat phase is needed. Automatic winter removals count each sea as one space for armies, then break equal distances by fleets first and province name. A convoyed attacker does not prevent retreat to its original province when otherwise legal.

Victory

A power wins by controlling 18 of the board's 34 supply centers. The game state and final result are recorded by the server. All players must follow the same map and adjudication rules.