In general, Id like to see the environment play a much larger role than it currently does in civ. That would include such concepts as tile attrition and true movement (both of which are planned mods by TheLopez, btw), as well as having a larger influence on technological progress. There is already a mod which does this to an extent (by TheLopez), though it only does a limited amount of what Ill describe below.
Environment, in civ, can be broken down into Starting Location, Primary Tile/Feature, Secondary Tile/Feature, and Landmass Situation. Each of these environmental conditions will affect a civs ability to research certain techs in its own ways through use of environment flags on technologies. For example, how can you develop Sailing, if you dont have a single tile of water within your entire empire? The obvious answer is that it should not be allowed. Another example, why would a civ living in a dense, highly productive jungle develop Agriculture? The obvious answer, as history has shown numerous times, is that they wouldnt. But the environment doesnt serve to just limit people, it also offers distinct advantages. For example, the Inca and Tibetans have (or have had) settlements at elevations where most people cannot survive (in civ terms, mountain cities) while the Inuit live in places where most would freeze to death (ice cities in civ terms).
Starting Location should affect which techs you start with (like whats done in the mod I mentioned previously, by TheLopez), but it should also affect the path of development by making the civ more likely to follow a certain path of tech development by making techs based on the Starting Location 20% cheaper, and thus more attractive to research.
Primary Tile/Feature is what I use to refer to the most common tile type and feature combination present within the civs cultural borders, whether that is grassland, desert, ice hill, plains forest, or some other combination of tile and feature. The Primary Tile/Feature of a civ also reduces techs based on it by 20%.
Secondary Tile/Feature (as above, but only a 10% reduction if there is no secondary, the civ gets an additional 10% to its primary)
Landmass (LM) Situation is what I use to refer to the civs placement on a landmass, which can either be Coastal, Interior, or Island. This environmental condition also serves to reduce the cost of related techs by 20%.
So, with all environmental conditions considered, a tech might be reduced in cost by as little as 10% or as much as 60% (and very, very rarely, even 70%). Now, using the standard tech tree, this would only have a small effect on the game, but if the tech tree were designed with this feature in mind, one could create techs which apply to only certain environmental conditions. Such techs could allow unique units, buildings, wonders, tile improvements, etc., that grant civ-specific, desired advantages, given a particular environment.
Prohibited techs would be those associated with an environment that the civ does not have access to. For example, a civ with 100 tiles in its cultural borders comprised of 4 tundra, 13 forested tundra, 12 hilly plains, 10 grassland, 20 plains, 15 coast, 14 ocean and 12 mountains would not be able to research (a hypothetical) Camel-Riding tech because the tech requires a primarily desert environment. This example civ would be primarily a Plains-dwelling, Coastal civ, with forested tundra secondary, and (lets just assume) a grassland Starting Location. This equates to the following bonuses:
Starting Location (grassland) = 20% reduction
Primary (plains) = 20% reduction
Secondary (forested tundra) = 10% reduction
Landmass Situation (Coastal) = 20% reduction
A few example techs with environmental conditions (from existing tech tree):
Fishing (Coastal LM Situation)
Sailing (Coastal LM Situation)
Agriculture (River Start Location & Primary/Secondary not jungle, ice, tundra, or mountain)
Horseback Riding (plains)
Environment, in civ, can be broken down into Starting Location, Primary Tile/Feature, Secondary Tile/Feature, and Landmass Situation. Each of these environmental conditions will affect a civs ability to research certain techs in its own ways through use of environment flags on technologies. For example, how can you develop Sailing, if you dont have a single tile of water within your entire empire? The obvious answer is that it should not be allowed. Another example, why would a civ living in a dense, highly productive jungle develop Agriculture? The obvious answer, as history has shown numerous times, is that they wouldnt. But the environment doesnt serve to just limit people, it also offers distinct advantages. For example, the Inca and Tibetans have (or have had) settlements at elevations where most people cannot survive (in civ terms, mountain cities) while the Inuit live in places where most would freeze to death (ice cities in civ terms).
Starting Location should affect which techs you start with (like whats done in the mod I mentioned previously, by TheLopez), but it should also affect the path of development by making the civ more likely to follow a certain path of tech development by making techs based on the Starting Location 20% cheaper, and thus more attractive to research.
Primary Tile/Feature is what I use to refer to the most common tile type and feature combination present within the civs cultural borders, whether that is grassland, desert, ice hill, plains forest, or some other combination of tile and feature. The Primary Tile/Feature of a civ also reduces techs based on it by 20%.
Secondary Tile/Feature (as above, but only a 10% reduction if there is no secondary, the civ gets an additional 10% to its primary)
Landmass (LM) Situation is what I use to refer to the civs placement on a landmass, which can either be Coastal, Interior, or Island. This environmental condition also serves to reduce the cost of related techs by 20%.
So, with all environmental conditions considered, a tech might be reduced in cost by as little as 10% or as much as 60% (and very, very rarely, even 70%). Now, using the standard tech tree, this would only have a small effect on the game, but if the tech tree were designed with this feature in mind, one could create techs which apply to only certain environmental conditions. Such techs could allow unique units, buildings, wonders, tile improvements, etc., that grant civ-specific, desired advantages, given a particular environment.
Prohibited techs would be those associated with an environment that the civ does not have access to. For example, a civ with 100 tiles in its cultural borders comprised of 4 tundra, 13 forested tundra, 12 hilly plains, 10 grassland, 20 plains, 15 coast, 14 ocean and 12 mountains would not be able to research (a hypothetical) Camel-Riding tech because the tech requires a primarily desert environment. This example civ would be primarily a Plains-dwelling, Coastal civ, with forested tundra secondary, and (lets just assume) a grassland Starting Location. This equates to the following bonuses:
Starting Location (grassland) = 20% reduction
Primary (plains) = 20% reduction
Secondary (forested tundra) = 10% reduction
Landmass Situation (Coastal) = 20% reduction
A few example techs with environmental conditions (from existing tech tree):
Fishing (Coastal LM Situation)
Sailing (Coastal LM Situation)
Agriculture (River Start Location & Primary/Secondary not jungle, ice, tundra, or mountain)
Horseback Riding (plains)