I found this method of slowing down exploration in the early stages of the game.
Edit the following file: /Assets/XML/UNITS/Civ4UnitInfos
Edit the following file: /Assets/XML/UNITS/Civ4UnitInfos
<TerrainImpassables>
<TerrainImpassable>
<TerrainType>TERRAIN_DESERT</TerrainType>
<bTerrainImpassable>1</bTerrainImpassable>
</TerrainImpassable>
</TerrainImpassables>
<FeatureImpassables>
<FeatureImpassable>
<FeatureType>FEATURE_JUNGLE</FeatureType>
<bFeatureImpassable>1</bFeatureImpassable>
</FeatureImpassable>
</FeatureImpassables>The value "1" forbids my scouts & warrirors and possibly settlers (haven't tested it) to cross either deserts and/or jungles.
However the terrain/feature will become passable with a road on it.
An efficient way of slowing down early exploration/expension.
G.