Columbus
1. Introduction.
Columbus is an attempt to recreate the excitement of exploring the New World. Unless modified below, the rules of standard Diplomacy apply.
2. Equipment.
2.1 Map.
This has three areas :-
a) Known World. Provinces with full names delimited by dashes ( - - - ) for sea provinces or solid lines ( ------- ) for land provinces.
b) New World. Provinces with numeric names (1-56) delimited by dots
( ...... ). At the start of the game it is not known whether these are land or sea.
c) Impassable. Cross-hatched areas.
2.2 Pieces.
Standard Diplomacy pieces for the five Powers :-
Netherlands    Yellow
England        Pink
France         Blue
Spain          Black
Portugal       Green
2.3 Coloured Pencils.
Use Green and Blue to denote Land and Sea provinces as they are explored.
3. Starting Position.
Netherlands    F(Net)
England        F(Eng)
France         F(Fra.?)
Spain          F(Spa.?)
Portugal       F(Por)
The starting coasts of the French and Spanish fleets are decided by their owners and specified in their first move orders.
3.1 Example.
Early 1490's
France    	F(Fra.wc)-NAO
Spain     	F(Spa.ec)-MAO
4. Sequence.
Instead of Diplomacy's years, Columbus has decades, starting from the 1490's. And instead of seasons it has early, mid and late decades.
So the sequence goes like this :-
Early 1490's   Moves
Mid 1490's     Moves
Late 1490's    Adjustments
Early 1500's   Moves
Mid 1500's     Moves
Late 1500's    Adjustments
Early 1510's   etc.
5. Exploration.
If a unit is legally ordered to move to an unexplored province - whether or not that order succeeds - a die is rolled to determine the province's character, using this table :-
1    SEA
2    SEA
3    LAND
4    LAND
5    LAND - NATIVE CENTRE
6    LAND - MAJOR NATIVE CENTRE
6. Coastlines.
If an explored land province has two or more coastlines that are not, or not yet known to be, connected, they should be marked as 'ec', 'wc', 'nc', or 'sc' as appropriate. Further exploration may render these markings unnecessary.
7. Move Not Possible.
If an army moves or supports into an unexplored province and exploration shows the province to be sea, then the move or support does not take place.
7.1 Example.
49 is land.
53 is land.
50 is unexplored.
Spain     	A(49)-50
Portugal  	F(53)-50
France    	F(MAO)-50
Exploration of 50 : SEA (die-roll=1)
The Spanish move fails - it is not possible. The Portuguese and French units stand each other out.
If Spain had instead ordered 'A(49) S Portuguese  F(53)-50', this support would have failed as well (not possible).
8. Unexplored Coastlines.
A fleet cannot make a move that depends on a piece of coastline that is not yet known to exist.
8.1 Example.
15 is land.
21 is sea.
22 is unexplored.
29 is land. Its two coasts have been marked 'ec' and 'wc'.
Late 1550's
France    	F(29.ec)-21
The French move is illegal.
8.2 Example.
15 is land.
21 is sea.
22 is unexplored.
29 is land. Its two coasts have been marked 'ec' and 'wc'.
Late 1550's
France    	F(29.ec)-21
England   	A(15)-22
Exploration of 22 : SEA (die-roll=2)
The English move fails (not possible), but the French move succeeds. The 'ec' and 'wc' markings on province 29 are no longer needed.
9. Supply Centres.
9.1 Home Supply Centres.
Shown        on the map. Each Home Supply Centre is garrisoned : it has an intrinsic strength equivalent to one unit which is added to a unit attempting to hold in the centre. If the centre is unoccupied then the garrison resists the entry of units belonginging to foreign Powers. Friendly units may enter the centre freely. Units may support the garrison itself if the centre is unoccupied, using 'G' in the support order to denote the garrison.
If a Home Supply Centre is occupied by a foreign Power :-
a) The garrison is destroyed.
b) The foreign Power does not count this centre towards its total, either for adjustments or victory conditions.
c) If the centre is unoccupied at the end of a mid-decade turn it reverts to the original owner, and the garrison is reinstated.
9.1.1 Example.
Spain     	A(Spa)-Fra
          	Fra is unoccupied
The Spanish move fails.
9.1.2 Example.
Spain     	A(Spa)-Fra
          	F(MED) S A(Spa)-Fra
France    	F(Fra) stands
The Spanish move fails.
9.1.3 Example.
Spain       A(Fra) stands
France      F(SAR)-Fra.wc
            F(NAO) S F(SAR)-Fra.wc
The French move succeeds.
9.1.4 Example.
Netherlands	F(NOS) S G(Eng)
France	F(DEN)-Eng
		F(NAO) S F(DEN)-Eng
		Eng is unoccupied
The French move fails.
9.1.5 Example.
Netherlands	F(NOS) S G(Eng)
England	F(NAO)-Eng
		Eng is unoccupied
The English move succeeds.
9.2 Native  Centres.
Mark these        when they are discovered. They are the same as Neutral Supply Centres in standard Diplomacy.
9.3 Major Native Centres.
Mark these        when they are discovered. These have a garrison with the strength of one unit. Units may support the garrison, which is denoted in the support order by 'G'. As soon as a unit enters the centre the garrison is destroyed and plays  no further part in the game (show this by marking the centre        ). The owning Power can build units in a Major Native Centre.
9.3.1 Example.
Early 1520's
50 is unexplored
46 is unexplored
Spain		F(SAO)-50
		F(MAO)-46
Portugal	F(Por)-MAO
Exploration of 50 : MAJOR NATIVE CENTRE (die-roll=6)
Exploration of 46 : SEA (die-roll=1)
F(SAO)'s move fails, the others succeed.
Late 1520's
Spain		F(SAO)-50
		F(46) S F(SAO)-50
Portugal	F(MAO) S G(50)
The Spanish move fails.
9.4 Notes on Supply Centres.
Ownership of a supply centre is transferred if it is occupied at the end of a mid-decade turn (as  in standard Diplomacy with Autumn turns). A Power can build on its own Home Supply Centre, and any Major Native Centres that it owns.
10. Victory Conditions.
If there are still unexplored provinces on the board, the winner is the first power to own 15  supply centres, or over half the total centres on the board, whichever is greater.
If there are no unexplored provinces on  the  board,  the winner  is  the first Power to own over half of  the total Centres on the board.
11. Designer Notes.
This variant first appeared as 'ExploroDip' at Manchester Grammar School in the 1970's. It was popular with my FTF Diplomacy playing friends in the sixth form, but failed to see the light of day since none of us were involved in the postal hobby at that time. When I got involved with the hobby in 1990 I started subbing to 'Moonlighting' and mentioned 'ExploroDip' to Richard Jackson who asked for a copy of the rules. As the rules had never been committed to paper and the map was long lost I started working on a new version, and here it is at last. 'ExploroDip' always seemed a bit of a naff name, so as it's 1992 I decided on 'Columbus'.
The game is obviously not meant as a historical simulation. What I was after was the flavour of exploration - looking for the North West Passage, wondering if it is there, trying to imagine the strategic implications of finding it. Any one game of Columbus is unlikely to be balanced, too much depends on the roll of the dice. But I hope that there is fun to be had from adjusting your plans to an ever changing geographical situation, and watching a different America emerge before the eyes of your questing fleets.

Peter Haslehurst
April 1992