The cost for bribing an enemy city depends on a number of factors. The formula below contains all the details; it is taken from an alt.games.civ2 post by Daniël Proost:
Cost = ( ( enemy gold + 1000 ) / ( distance + 3 ) ) x citysize
I am not sure which distance is meant in this formula. It is probably the distance between the city and its capital. However, the cost depends on the square your Diplomat or Spy bribes from. It often pays to try to bribe from different squares - I have observed the cost vary by as much as 20%. At any rate, the distance is also influenced by the following factors:
Courthouse in city half distance
Enemy government is Communism max. distance is 10
Enemy has no palace distance = 32
The following (cumulative) modifiers apply to the cost for bribing:
City in disorder -50%
No units in city -50%
City was yours before -50%
Spy is bribing -16%
Veteran unit is bribing -33%
Cost = ( ( enemy gold + 1000 ) / ( distance + 3 ) ) x citysize
I am not sure which distance is meant in this formula. It is probably the distance between the city and its capital. However, the cost depends on the square your Diplomat or Spy bribes from. It often pays to try to bribe from different squares - I have observed the cost vary by as much as 20%. At any rate, the distance is also influenced by the following factors:
Courthouse in city half distance
Enemy government is Communism max. distance is 10
Enemy has no palace distance = 32
The following (cumulative) modifiers apply to the cost for bribing:
City in disorder -50%
No units in city -50%
City was yours before -50%
Spy is bribing -16%
Veteran unit is bribing -33%
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