By Stephen Agar and Richard Walkerdine
I don't believe that Multiplicity enjoys the popularity that it deserves. Richard Walkerdine came up with the basic idea for multiple units in the early 70's and I remember a game running in the original Mad Policy in 1975-76. Keith Black revised the rules to make them comprehensive and the resulting Multiplicity II was published in Pigmy #16 August 1978. This is a drastically simplified version.
0. The regular rules of Diplomacy apply, save where varied below.
1. Initial Placement. Players may choose whether the units originally starting on their home supply centres are armies or fleets, and Russia is free to build on either coast of StP provided it is specified.
2. Multiple Units. The essence of Multiplicity is the multiple unit, thus multiple units may exist subject to the rules below (Eg. 2A, 3A, A/F, 2A/F etc). Each component part of a multiple unit requires a supply centre to support it. A multiple unit may not distribute its supports into different spaces, but need not support with its full strength.
3. Merging. A multiple unit is formed by specifically ordering two or more existing units of the same nationality to merge. Merging takes place by ordering the units concerned to merge in the same space (Eg. A(Mar) & A(Pic) MERGE 2A(Bur). All forces attempting to merge are deemed to be supporting each other (except for A/F's - see below), thus if in the above example Germany ordered A(Mun)-Bur the merge would still succeed. Support for a merge in a given space may also be given by a non-participating force (Eg. A(Par) S MERGE (Bur)). If part of a merge fails due to one of the component units failing to reach the space in which the merge is to take place, then any other units ordered to merge will follow their movement orders unaffected (even if this results in a normal move as opposed to a move). Multiple units may also be formed by a player building on a home supply centre that is already occupied.
4. Combat. A multiple unit stands, moves and fights with a strength equal to the number of units present in the merged unit. Thus a 2A will displace an unsupported army. All support given by a multiple unit is cut by any attack on the multiple unit.
5. A/F Combinations. The usual Abstraction A/F rules are not used in Multiplicity. However, A/F combinations are permitted along the same lines of other multiple units and an A/F may move into a sea space (as opposed to a coastal space) provided it is seaworthy (the number of fleets is the same or exceeds the number of armies). Thus a 2A/F could not move into the MAO, but an A/2F could. An A/F combination in a multiple coast space occupies a specific coast. A seaworthy A/F can be created in a sea space (Eg. A(Lon) & F(MAO) MERGE A/F(ENG)), but in this event the army cannot support the merge.
6. Convoys. A/F units can also convoy armies according to the usual Diplomacy rules, provided that the sum of the A/F and the unit(s) being convoyed is seaworthy. Thus an A/3F in ENG could convoy a 2A(Lon)-Pic. Only armies or all army multiple units may be convoyed.
7. Splitting. During a movement season a player may SPLIT a multiple unit into two or more component parts (E.g. 4A(Par) SPLIT A(Pic), 2A(Bur), A(Gas)). The movement of each unit splitting follows the usual rules, but a unit may not SPLIT and MERGE in the same move. If a component of a multiple unit fails to split it will remain part of the multiple unit and is considered never to have split for the purpose of adjudicating any attacks on that multiple unit.
If the failure of any component of the A/F to split means that the resulting A/F at sea would be unseaworthy, then all units attempting to split from the multiple A/F will fail. There is no exception to the rule that an A/F at sea must be seaworthy.
8. Retreats. Merges and Splits are not allowed during retreats. If two or more forces are ordered to retreat to the same space, the stronger unit will succeed.
First published in Spring Offensive No.58