How to Play | Atlas Diplomacy

Interactive Tutorial

Practice holds, moves, supports, convoys, and builds on a live mini-map — command Turkey through a guided campaign.

The Atlas Diplomacy Field Manual

The Definitive Guide to Strategy, Negotiation, and Adjudication

Welcome to Atlas Diplomacy — the modern war room for Allan Calhamer's classic game of international intrigue. Diplomacy is a game of pure skill, negotiation, and strategic coordination. There are no dice, no cards, and no luck. Your only assets are your units, your word, and your ability to read the minds of your rivals.

Players are randomly assigned to command one of the seven Great Powers of early twentieth-century Europe: Austria, England, France, Germany, Italy, Russia, and Turkey.

The Game Ends When

→One player owns 18 or more Supply Centers by Winter of any given year — a solo victory.
→All surviving players unanimously agree to draw. Survivors with more Supply Centers score higher.
→The configured End Year is reached (1915 by default). All survivors score based on their final Supply Center count.

The Map

The map represents Europe at the dawn of the 20th century, divided into 75 distinct provinces classified into three types.

Inland Provinces

Occupiable only by Armies. Examples: Paris, Munich, Vienna.

Sea Spaces

Occupiable only by Fleets. Examples: North Sea, Mid-Atlantic Ocean.

Coastal Provinces

Occupiable by both Armies and Fleets. Examples: Brest, Trieste, Sevastopol.

Supply Centers

Of the land provinces, 34 contain Supply Centers (SCs), marked on the map. These are the most strategically important territories:

→Controlling a Supply Center allows a Great Power to support and maintain one military unit.
→A Power's total unit count must always equal its current count of controlled Supply Centers.
→SC ownership is updated only during the Winter Adjustment phase, based on which units occupy them at the end of Fall.

Map Notes

Split Coasts

Bulgaria, St. Petersburg, and Spain have split coasts. A Fleet moving to these provinces must specify which coast it occupies, and can only reach provinces adjacent to that coast. The Fleet still occupies the entire province for all other purposes.

Full-Access Coastal Provinces

Constantinople, Denmark, and Kiel are coastal but do not have split coasts — Fleets may move to any adjacent province. Note that players may not convoy through coastal provinces of any kind.

Invalid Orders Are Allowed

Players are permitted to input invalid orders. Purposefully miswritten orders are a legitimate gameplay tactic. The fact that a move appears possible in the Atlas Diplomacy UI does not guarantee it is valid.

Phases

Each year in Diplomacy consists of a series of sequential phases, cycling until the game ends. Players should negotiate and submit their orders during each Diplomacy phase before the timer expires. All orders are revealed and resolved simultaneously.

Spring Diplomacy→Spring Retreat *→Fall Diplomacy→Fall Retreat *→Winter Build *

* Skipped automatically when no action is required.

Phase	What Happens
Spring Diplomacy	Negotiate alliances and submit orders. All orders resolve simultaneously.
Spring Retreat	Units dislodged in Spring must retreat to an adjacent vacant space or be removed. Skipped if no units were dislodged.
Fall Diplomacy	Identical to Spring. SC ownership is evaluated after this phase resolves.
Fall Retreat	Identical to Spring Retreat.
Winter Build	Players with surplus SCs build new units at vacant Home SCs. Players with fewer SCs than units must disband.

Win Conditions

Solo Victory

Control 18 or more Supply Centers by the end of any Winter phase. All other players — eliminated or surviving — have lost.

Draw

All surviving players unanimously vote to end the game. Survivors with more Supply Centers score higher.

End Year

The game ends after the Winter of the configured end year (default: 1915). All survivors score based on final SC count.

Orders

During a Movement Phase, every unit must be given exactly one of the following four orders. If no order is given, a Hold order is automatically issued.

Hold

A PAR H

The unit remains in its current province and defends its position with a base strength of 1. If attacked by a unit of equal attack strength, ties go to the defender.

Example: An Army in Paris holds its ground and does not move.

Move

A PAR - BUR

The unit attempts to march into an adjacent province with a base strength of 1. Armies can move to any adjacent inland or coastal province; Fleets can move to any adjacent sea space or coastal province (respecting coastlines). If successful, the unit vacates its starting province. If it fails, it remains in place with a hold strength of 0.

Example: An Army in Munich moves to Burgundy; a Fleet in the English Channel moves to Brest.

Support

A BUR S A PAR HA BUR S A PAR - PIC

Because every unit has an equal base strength of 1 and ties go to the defender, any contested battle requires cooperative strength. Supporting adds +1 defensive or offensive force to another unit.

Support Hold — adds +1 defensive strength to a static unit in an adjacent space. The supporting unit must be adjacent to the province of the unit receiving support.

Support Move— adds +1 offensive strength to a unit moving from an adjacent space into a target space. The supporting unit must be adjacent to the destination, not the moving unit's starting space.

Convoy

F NTH C A LON - BELA LON - BEL

Fleets in sea spaces can chain together to transport an Army across water, allowing it to move to non-adjacent coastal provinces. Only Fleets in Sea spaces can convoy — Fleets in coastal provinces cannot. The Army must start and end on land. If any convoying fleet is dislodged during the same turn, the convoy fails and the army does not move.

Example: An Army in London moves to Belgium while a Fleet in the North Sea convoys it. Multiple fleets can chain to convoy an Army across vast distances.

Cutting Support

A supporting unit's support can be cut — reducing its added strength to 0 — if it is attacked by an enemy unit during the same turn. Support is not cut if the attack comes from the very unit being attacked by the supported move.

Example: If an Army in Berlin attacks Silesia with support from Munich, and any unit other than the unit in Silesia attacks Munich, the support is cut.

Combat

All orders resolve simultaneously. The following core rules govern how conflicts between units are adjudicated.

Equal Strength Bounces

If two or more units move to the same space with equal force, they bounce — all remain in their starting provinces.

Dislodgement Requires Superior Force

To dislodge an enemy unit, your move must have attack strength strictly greater thanthe defender's total defensive strength including all supports.

No Self-Dislodgement

A player cannot dislodge their own units, even with allied support. Attacking your own unit with superior force results in a bounce.

No Direct Swaps

Two adjacent units cannot swap positions without a convoy. An Army in Paris moving to Burgundy and an Army in Burgundy moving to Paris will always bounce.

Retreats

Units that are dislodged must retreat during the subsequent Retreat Phase. A unit can retreat to any adjacent province, with the following exceptions:

→It cannot retreat to a province occupied by another unit.
→It cannot retreat to the province from which the dislodging attack originated.
→It cannot retreat to a space that was vacant but was the site of a bounce during the immediately preceding movement phase.

If a player has no valid retreat options, or fails to submit a retreat order before the phase deadline, the dislodged unit is disbanded. If multiple dislodged units are ordered to retreat to the same space, they both fail and are disbanded.

Builds

During the Winter phase, players align their military size with their economic power (SC count). Players either build new units or disband existing ones.

Builds

→If a player controls more SCs than they have active units, they may build new units.
→New units can only be built in unoccupied Home Supply Centers that the player currently controls.
→If all home SCs are occupied or owned by other players, the player cannot build — even if they have extra SC capacity.

Disbands

→If a player controls fewer SCs than they have active units, they must disband units until the counts match.
→If a player fails to submit disband orders before the deadline, units are auto-disbanded: the unit farthest from any owned SC is disbanded first. Among ties, Fleets are disbanded before Armies.

That's it. You're ready to conquer Europe. Master these rules and the rest comes down to diplomacy, timing, and nerve.

Atlas Diplomacy Features

To make this complex board game seamless online, Atlas Diplomacy provides a modern digital war room backed by features designed to protect game health, competitive integrity, and fair play.

Interactive Drafting & Path Indicators

Orders are input visually on the map using a radial command dial — no text strings required. While drafting, moves are projected as live path indicators so you can verify your plans before finalizing. Navigate history using the arrows on either side of the Season / Year indicator.

Secure Communication Channels

The heart of Diplomacy is communication. The integrated messaging center supports global announcements, secret private threads, and multi-player coalition channels — all without leaving the game screen.

Competitive ELO Ranking

A customized multi-player ELO system rewards strategic excellence. Your final rating adjustment is determined by your conquered territory relative to all other survivors and weighted against your expected score based on pre-game ELO. Each game type (Standard, Rapid, Gunboat, Siege) has its own separate ladder.

Three Active Game Limit

Atlas Diplomacy enforces a strict limit of three concurrent active games per player. This prevents abandonment, keeps players responsive to diplomatic messages, and preserves the social mechanics that make Diplomacy exceptional.