Multiplicity (I) (rn05)

by Richard J. Walkerdine

1. The regular Diplomacy board is used and the normal (1971) Rules of Diplomacy apply, except as noted below.

2. There are three seasons to the year: Spring moves; retreats and Autumn moves; retreats and Winter builds.

3. In addition to the usual single units a player may own multiple units of the following types: multiple Armies (2A, 3A, etc); multiple Fleets (2F, 3F, etc); and Army/Fleet combinations (A/F, A/2F, 2A/2F, etc). Note however that in A/F combinations there must not be more Armies than Fleets.

4. To sustain themselves on the board multiple units require the resources of as many supply centers as there are single units within the multiple. Multiple Armies and multiple Fleets attack, support and stand with their multiple strength. A/F combinations operate with their multiple strength only if they are standing in, attacking into or supporting into a coastal province. If they are standing in, attacking into or supporting into an open-sea space an A/F may only use the strength of it’s Fleet component. If an A/F is in a coastal province, the Army component only may attack or support into an adjacent inland province.

5. A player may build single or multiple units on any unoccupied home supply centers owned by him in a Winter season in the normal way. He may also build any units due his on home supply centers already occupied by his own forces, thus creating multiple units on them. Fleets can of course only be built on coastal provinces.

6. During a Spring or Autumn season, a player may MERGE two or more units to form a larger multiple unit. All units involved in the Merge must be adjacent to, or already on, the province on which the multiple unit is to be formed. For the purpose of adjudicating possible stand-offs etc. all units involved in a Merge are considered to be supporting each other. Support can also be given to the Merge by outside units.


FRANCE: A Pie + A Par + A Gas MERGE = 3A Bur, A Mar S 3A’s – Bur

GERMANY: 3A Bur stands

(The German 3A Bur is attacked by the three merging French armies supported by the fourth French A Mar, and therefore has to retreat.)

7. During a Spring or Autumn season, a player may SPLIT a multiple unit into two or more smaller ones. This is the opposite of the Merge order except that the splitting units cannot support each other. If however one or more units from the original multiply is to remain on the original province, these units may furnish support to any other units. Support for the Split can also be given by outside units.


FRANCE: 3A Bur SPLIT = A Par A Bur A Mun, A Bur S A Bur-Mun, A Gas S A Bur-Par

GERMANY: A Mun stands, 2A Par stands

(The German A Mun is forced to retreat by the supported French attack, but the 2A Par is strong enough to force a stand-off. France ends with 2A Bur, A Mun, A Gas.)

8. Merges and Splits are not allowed in a Retreat.

9. The first move of the game is Spring 1901. Before this however there is a Winter 1900 season for players to make the initial placement of their units. Armies, Fleets, multiple and combinations may be placed on a player’s home supply centers at his discretion – subject to him having enough supply centers to sustain the units. Russia, for example, might choose to begin the game with a 2A StP and an A/F Sov, which would be as much as it’s four centers could sustain.

A/F Rules

1. All the normal rules for Diplomacy (1971 rule book) apply, except as amended below.

2. The basis of the variant is that in addition to the usual single units, a player may form multiple units by combining an Army and a Fleet to form an A/F combination.

3. During a move season a player may order the two units to MERGE and so form an A/F. Units of different nationalities may not Merge. The units attempting to merge must be capable of moving to the province and coast on which the merger is to take place. The units attempting to merge are considered to be supporting each other (see Rule 4). Additional support may be given to the merger as a whole by non-participating forces (eg. A(Bur)SM(Pic): where M is the abbreviation for a Merger).

4. The units to be merged must be ordered to do so (eg. if France had F Bre, A Par and A Pic and ordered F(Bre)+A(Par)M: A/F(Pic), then if A(Pic) could not move, this would cause the merger to fail). Merger is a separate order and units may not also seek to convoy or support outside the merger. However, as the Merger order involves movement to the province where the merger is to take place, a merger may also be an attack upon any forces currently occupying that province (as with normal movement rules).

Example: France: F(Bre)+A(Par)M: A/F(Pic); A(Bur)SM(Pic)

England: F(Pic)-st.; F(ENG)SP(Pic)st.

The English F(Pic) is attacked by the two French units, supported by the third French army and having only one other support, it therefore has to retreat.

5. Having been formed by a Merger, A/Fs are then able to move at the normal movement rate, to any sea space on the board, as well as to any coastal province. When occupying a split-coasted province the specific coast must be specified as for fleets.

It is possible for a country to have fleets on both coasts of a split-coasted province, but they may not act together as a multiple unit or merge with each other.


a. Once formed, an A/F may stand in, or move to a given province with the strength (“displacement strength”) of two units, plus the number of valid and uncut supports.

b. The units merge in a province with the displacement strength equal to the total number of valid and uncut supports for those forces to merge, plus the two units involved in the merger.

c. In all cases an Army does not count towards the displacement strength if the given space is a sea area, and fleets only count towards the displacement strength when merging in a coastal land province or attacking into such an area. The Army component of an A/F may give support into an inland province, the fleet may not. A move or merger succeeds if its displacement strength exceeds that of the opposing forces (see example in Rule 4).

7. During a move season the player may order any A/F to DIVIDE into it’s component units. Each component must be ordered to move away to a different province as only a single unit or combination may occupy a particular province. The movement of each component follows the usual movement rules. Unlike a merger, components dividing from an A/F cannot support each other whilst doing so. Only a component remaining in the original province may give support to a specific component which is moving away.

Outside units may also give support, as with mergers (see Rule 4). Supports for the remaining unit are nullified if the other component fails to leave.

Example: France: A/F(Pic)D: F(Pic), A(Bel), F(Pic)SA(Pic)-Bel; F(Bre)-ENG

Germany: F(Bel)st.; F(ENG)SF(Bel)-st.

The English F(Bel) is forced to retreat by the supported French attack, as it’s own support from F(ENG) is cut by the stand-off attack by the French F(Bre). Either component from the division of an A/F may also merge once again in the same season as the previous division took place, as long as this does not involve any further movement.

8. Mergers and divisions are not allowed during retreats when an Army and Fleet attempts to retreat to the same space. The Army is given priority.

9. An A/F may be ordered to split it’s available support between two adjacent provinces, and need not support with all it’s available strength. In this case an idle unit does not protect the given support from being cut.

10. The component units of a non-moving A/F may give separate supports into either the same or separate provinces. A single attack against the A/F will only cut one of these separate supports. Where the A/F is the subject of two or more independent attacks, only the strongest attack is considered to have cut the A/F’s support, the other attacking units have no effect.

11. If an attack upon the non-moving and supporting A/F would cut one of it’s two separate support orders, whichever is written second will be taken as the lower priority and will be the one which is cut, unless the player clearly numbers the separate support orders to indicate their priority.

12. An A/F requires one supply center to maintain each of its component parts, just as if they were individual units. If it possible to build on a home center that is already occupied, as long as the center is only occupied by a single unit and whatever is built is the other unit type – thus forming an A/F.


Before we actually start there are a couple of queries from players that we’d better clear up first:

Units from different countries are not allowed to Merge together. Multiplicity rules 6 and 7 state that a player may Merge or Split units, thus implying that this refers only to units of a single country.

We have to decide what to do about cutting support. The only difficult case I can foresee is then a larger multiple is doing some supporting and is attacked by a smaller multiple; so I’ll rule that the largest multiple’s support is cut only up to the strength of the attacking multiple. That is, if a 3A is supporting somewhere and is attacked by another country’s 2A then 2/3 of the support is cut, i.e. the 3A ends up giving only the equivalent of a single A support.

Can units with a fleet component be convoyed? The answer is no, and we’d better also rule that it takes a 2F to convoy a 2A and a 3F to convoy a 3A etc. I’m tempted to rule that the army component of a 2A/2F unit, for example, does not stop the unit convoying an A or 2A – anyone disagree?

How do separate coasts affect multiple fleet units? [For example consider: F GoB + F Bar MERGE = 2F StP(?C)]. No problem, they can’t do it. The Merge order wouldn’t be allowed if it meant a unit was making a move that was geographically impossible.

What happens when a single unit attacks a multiple unit that is giving support to different pieces, which support is cut? Year, that’s a nasty one. One solution would be to request the attacking player to submit a preference list for which possible supports be is trying to cut – but that would mean a rather unfortunate precedent of making orders conditional on current events and that’s on thing I’m very wary of. I think the best solution is for the GM to decide which support is cut by random methods – a die roll for example. Okay?

When one unit in a multiple is standing and the rest are supporting is it correct to say an attack on that multiple by a single unit will produce no effect? Sounds reasonable, so the answer is yes. Furthermore if the multiple was attacked by a 2A then one of those armies would flounder against the single standing unit and the second army would cut one the supports as outlined in the previous paragraph.

How can a multiple unit give support to different pieces? I thought the whole point of your rules was to avoid this and the resulting complications. Nothing of the kind. I’ve never said that was going to be an uncomplicated game – quite the reverse in fact. No, the capabilities of multiple units stay as we’ve already agreed.