Designing Maps For Diplomacy Variants

by Stephen Agar

This article aims to distil what little I have learned on the subject of constructing variant maps for Diplomacy variants. Essentially I am talking about historical or fantasy variants which have the basic Diplomacy rules at the core, i.e. the army/fleet distinction with usual combat and movement rules - the group often referred to as map-change variants. I have also assumed that the game is to be run on the same sort of scale as regular Diplomacy, that is to say that at the beginning of the game each player will have 3-5 home centres.

A good scenario for a variant is one which allows you to use it for a number of Powers (say 5-9) with a reasonable geographic spread. Often the inspiration for a variant will come from a historical setting for which you may already have a basic map available. The first thing to do is to determine the identity and distribution of the Powers insofar as they are not already determined for you by the confines of history. Of course the only limits on the setting for a Diplomacy variant is the imagination of the designer, Diplomacy variants already exist which are set in ancient times, medieval europe, the New World, the present day and even outer space. The principles remain the same. I do believe that the choice of scenario is important - most players will be far more enthusiastic about leading a Macedonian phalanx into Persia or recreating the Normandy landings than they will be in playing on abstract maps with abstract names.

To an extent any map bound by historical precedent will impose limitations on the geographical relationship of the players to each other. The key aim is to ensure that each power has at least three and preferably more directions in which to expand (although some may be easier than others). At the onset of the game there must be a choice of strategy open to the players. However, the number of home centres need not be the same for each Power. In Diplomacy Russia starts the game with 4 units rather than the usual 3, although if you are to maintain play balance (see below) any increase in strength should be tempered by geographical restrictions preventing the concentration of too much Power in one part of the board in the hands of one player.

Neutral Supply Centres

Assuming that your variant is to follow the features of the regular game and have a number of unoccupied neutral supply centres, then the positioning of the neutral supply centres will have a significant effect on the conduct of the game in the early stages and will affect the likely routes for expansion that each Power may adopt at the start of the game.

I believe that it is better if every Power can have a guaranteed build in the first game year, assuming no tactical disasters. This is certainly true of Diplomacy where it is unusual for any Power not to have at least one build in 1901. Some Powers may have a good chance of a second build and even more may be occasionally possible.

I believe that it is better to group neutrals together to construct an area of the board which at least two and preferably more Powers can enter early on in the game to make some gains, and thereafter provides a fertile battleground. You will note that in regular Diplomacy all the neutral supply centres are concentrated in four areas of the board, namely, the Balkans, Scandinavia, the Low Countries and the Iberian peninsula. Tunis is the exception because of the need to provide Italy with a guaranteed build in the first game year. On the other hand if neutral supply centres are placed in isolated locations here and there, they either become easy targets for a single player or become the scene for stand-offs in the first game year. Good diplomacy is encouraged by encouraging situations where more than two players are involved in an area of the board and this is often best achieved in the early stages by grouping neutrals together.

How many neutral supply centres should you have? I would argue for a balance not dissimilar to regular Diplomacy which with 22 home centres has 12 neutrals (a ratio of 1:0.55). That means that roughly one-third of the centres on the board should be neutrals. Of course, this is not a hard and fast rule, but if you have too many neutrals the early stages of the game will last a long time, while if you have too few neutrals you will force players into a mid-game situation before they have had a chance to achieve some initial growth and build up trust in their allies.

How to Avoid Overcrowding the Map

There are two quite separate aspects to play balance, the first is the balance inherent in the ratio of units and unit types to the size and geographical make up of the board and the second is the question of whether all players have a reasonable chance of winning. I would like to put aside the latter and concentrate on the former.

The ratio between occupied spaces and unoccupied spaces must be sufficient to allow for freedom of manoeuvre, but not so large as to make the game unduly long to play because all the units are so far away from each other. In this respect, I take the view that regular Diplomacy has the balance about right and suggest that we can formulate some guiding principles from an examination of what makes regular Diplomacy work.

Although some spaces are used more than others, the regular Diplomacy board has some 75 spaces to a maximum of 34 units, a ratio of 2.2 spaces to every unit. I would suggest that a designer developing a new map-change variant which does not incorporate either special movement rules or multiple units would do well to ensure that for every unit on the board there is at least 2 spaces and not more than 21/2 spaces. Any less then the board becomes crowded, any more then the board becomes too large.

Can Diplomacy tell us anything else about designing a board? Of the 22 home supply centres, 6 are not in coastal spaces and thus can only be taken by an army. Thus fleets can capture 16 home centres and armies can take all 22 centres - a ratio of just over 1:1.38. At the beginning of the game the ratio of fleets to armies is 9:13 or 1:1.44. Well 1.38 is not that far from 1.44, so you can argue that if Allan Calhamer got it right there is something to be said for saying that the initial balance of fleets to armies should be in the same approximate region as the ability of those units to occupy the home supply centres on the board. You may think I'm wrong, but I put it to you as a suggestion.

Let me give you an example. Suppose a new big variant was developed with 29 home supply centres, 10 of which are inland. Using Diplomacy as a yardstick would suggest that another 16 neutral supply centres would be appropriate, with the board having around 100 spaces in total and initial home units in the region of 18 armies and 11 fleets. Of course, these are only guidelines, but they will produce a map with comparable unit and space densities to the regular game, assuming you are content to use those ratios.

The above is merely a theory and I merely put it forward as a guideline against which virgin variants can be compared.

Beware Stalemate Lines

As we all know. a stalemate line is a series of occupied linked spaces on the board which can be defended successfully no matter how it is attacked by any combination of forces on the other side of the stalemate line and contains sufficient supply centres within it to support the armies and fleets needed to support it. Regular Diplomacy has a few stalemate lines, mainly running SE-NW through Switzerland.

A variant can be ruined if too many stalemate lines exist on the board for as soon as one player gets an upper hand, the other players can retreat behind stalemate lines and the game comes to an abrupt inglorious conclusion. Some variants avoid stalemate lines through the rule mechanics themselves, for example it is hard to imagine a stalemate line occurring in a game of Multiplicity, as the aggressor could simply use a multiple unit to break through.

The hallmark of a stalemate line is a series of linked spaces that have noticeably more spaces bordering the stalemate line on one side than they have on the other. This allows the line to be supported by more units than the opposing forces can bring to bear on the line from the other side. Hence, you should avoid long thin spaces which traverse several spaces on either side, such as Galicia or Munich as these usually provide the basis of stalemate lines.

Sea spaces are crucially important in the construction of a stalemate line as they are spaces which can only be attacked and supported by a particular type of unit (i.e. fleets). For example 3 fleets in NAO, MAO and Por can form an impassable barrier that can prevent any number of fleets emerging from the Mediterranean. In an ideal world such bottle necks as the straits of Gibraltar should be avoided. Particular problems will arise if any of the Powers in a game are landlocked, because they will never be able to build any fleets!

Play Balance

By this I mean real play balance in the sense of making sure that all the players have a reasonable chance of success. Note that I think that only a reasonable chance of success is necessary, not that each player should have an equal chance of success. An equal chance of success can only be achieved with an abstract or semi-abstract symmetrical board (such as used in the 5 Italies variant by Mike Lea) which may not prove to be the most interesting setting for a game.

To an extent the only way to make a firm judgment of the play balance inherent in a variant map is to play a few games and see what happens. However, think that there is an elementary test that you can apply to any board to see if any Powers have a substantially greater chance of winning than the others.

Although I don't want to reduce variant design to basic mathematics I believe that something can be learnt from counting up exactly how far each Power has to travel to occupy the number of centres needed for victory, as this provides a good indication of the strength of the Power concerned.

If you apply this test to regular Diplomacy you get the following results:

Distance to 18 Centres

Russia = 2.33

Germany = 2.50

Austria = 2.86

France = 2.82

Italy = 3.00

England = 4.00

Turkey = 4.00

But of course, that is not the whole story, some Powers are far more vulnerable to attack and tend to be eliminated early on. One way of measuring the vulnerability of a Power is to count the number of supply centres within 3 spaces of that Power's home centres and then consider how many of those centres are enemy home centres, the more home centres nearby, the more vulnerable the Power will be to attack. For Diplomacy the results are as follows:

% of S.C's <= 3 Spaces which are enemy home S.C.'s

England = 28.57%

Turkey = 42.86%

Russia = 45.83%

Italy = 50.00%

Germany = 52.17%

France = 55.00%

Austria = 63.16%

I am not saying that you can read too much into statistics like these, but I think that they do have some validity when examining the play balance of a variant. The significance of these figures is not the order in which Powers are ranked, but the extremes they disclose. From the above figures it is clear that Russia and Germany are the strongest Powers on the board, that England and Turkey are the safest and that Austria is the most vulnerable.

Diplomacy may be imbalanced, but it does work and works well. Therefore, I would suggest that it is wrong to get too obsessed about making a board exactly equal. Allow flavour of the period or world you are recreating to come through and accept that some countries will be marginally stronger than others and have a greater degree of tactical choice.

A similar exercise can be conducted on any variant map, the more similar the figures for each Power, the more accurately balanced the map will be.

Permit me to suggest a few basic rules when designing variant maps:

1. Try to make sure that no Power has to go further than 50% more to reach victory than the Power which has to travel the least distance.

2. Try to balance the map so that no Power has a higher % of enemy home centres within 3 spaces that exceeds double the % of enemy home centres enjoyed by the most secure Power.

3. Never have three or more home centres belonging to two or more Powers bordering each other at the start of the game. A game will have no chance to develop if a supported attack can be made on a home centre in the first move.

4. Try to avoid having any two home centres belonging to two players adjacent (Eg. Trieste and Venice) as that denies both players a degree of flexibility and peace of mind in the first move of the game.

I should add that Diplomacy doesn't satisfy the above tests (though it does comes close).

I hope that this article may encourage some of you to design new maps for Diplomacy variants based around whatever period of history or flight of fancy interests you (and I will be happy to help any budding designers and publish the results). Although some of the principles discussed above do have universal application, I doubt whether the comparisons I have made with regular Diplomacy would still be valid if the movement or combat rules are altered too much. Maybe I will follow this article up with a piece on rule-change variants.

Putting Zeus IV to the Test

Having spent a couple of pages suggesting guidelines for variant map design, let's examine a real variant which you will find immediately after this article. Zeus IV is a small world variant by Chris Northcott which does not alter the basic rules of Diplomacy at all, save for allowing the players to determine their initial builds.

The relevant statistics for Zeus IV are as follows:

Home S.C's = 21 (coastal); 3 (inland)

Neutral S.C's = 14

Total number of Spaces = 83

That gives a maximum of 38 units moving around in 83 spaces, almost exactly an average of 2.2 spaces per unit, which is the same as regular Diplomacy. I would conclude that the unit density should be about right.

Distance to 20 Centres

UK = 2.41
Soviets = 2.66
China = 3.14
USA = 3.27
Germany = 3.40
Italy = 3.43
Japan = 3.57

Well, the UK has to go further for victory than Russia does in the regular game, but even Japan who comes out bottom isn't placed as badly as England and Turkey in Diplomacy. Obviously the UK and the Soviet Union do reap the benefits of starting the game with 5 and 4 units respectively.

% of S.C's <= 3 Spaces = enemy home S.C.'s

Japan = 37.50%
Germany = 44.44%
USA = 47.06%
Soviets = 47.83%
UK = 48.15%
China = 52.63%
Italy = 52.95%

Japan may have to go the furthest for victory, but it has the safest position. Italy comes out badly on both tables, suggesting to me that it is the weakest Power.

To my mind Zeus IV looks better balanced than Diplomacy, because the extremes in play balance are not so far apart. The difference between the strongest and the weakest on each table are only 1.16 and 15.45% as against 1.67 and 34.59% for Diplomacy. Undoubtedly Zeus IV is helped by the fact that there are no corner positions on the board which enables the relative safety of the position of the Powers to be made more equal. A mere 6% separates five out of the seven Powers on Table 2, a negligible difference. Admittedly, the UK and the Soviet Union are strong, but no stronger than Russia and Germany in Diplomacy.

Assuming that the thrust of this article is not absolute rubbish, I would conclude that on the face of it Zeus IV is fairly well balanced and should play well.

I hope that this article may encourage some of you to design new maps for Diplomacy variants based around whatever period of history or flight of fancy interests you (and I will be happy to help any budding designers and publish the results). Although some of the principles discussed above do have universal application, I doubt whether the comparisons I have made with regular Diplomacy would still be valid if the movement or combat rules are altered too much. Maybe I will follow this article up with a piece of rule-change variants.

First published in Spring Offensive No.5 (October 1992)


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