Campaign Map Editing (RTW & M2TW)

Changing or creating a new campaign map is a very similar process in Rome and Medieval II -Total War.

Essential reading for both is *How to make an entirely new campaign map by Myrddraal.

GrnEyedDvl's Introduction to Mapping Lesson's 1 2 & 3 provides a focus on M2TW mapping.

Map Files

Modifications to the map will involve files in
data/world/maps/base
data/world/maps/campaign/campaign_folder
data/text (regions_and_settlements_names_campaign_name.txt only)

the files in the base folder may be transferred into your imperial_campaign, barbarian_campaign or provincial_campaign folder (note that provincial campaign folders are not functional in M2TW 1.1).

The most relevant files in those folders are:
descr_regions.txt
descr_terrain.txt - must include size of map_regions.tga
descr_strat.txt
map.rwm
map_climates.tga - 2x map_regions.tga size plus 1 pixel on height and width* (set climate type in region for strat map and battle map terrain generation)
map_ground_types.tga - 2x map_regions.tga size plus 1 pixel on height and width* (set terrain type on strat map and key for generation of terrain type on battle map)
map_features.tga - same size as map_regions.tga (sets rivers, cliffs and volcano positions)
map_heights.tga - 2x map_regions.tga size plus 1 pixel on height and width* (set terrain topology on battle map)
map_heights.hgt (if used)
map_regions.tga (set regions and their bordery on strat map map)
map_roughness.tga - size = 2x map_regions.tga (set topology of strat map)
map_trade_routes.tga - size = same as map_regions.tga (set area which would always reveal on strat map even if it is under fog of war)

*where map sizes are marked as plus 1 pixel note that the map file is expanded to use the full tga size including the extra pixel. Do not add a 'blank' pixel around the edge.

Others are:
radar_map1.tga the small map that appears at bottom left corner of campaign map - Note: making this tga too large can cause a crash at 2/3rds way along loading bar.
radar_map2.tga the enlarged version of the above - should be twice the size as radar_map1.tga
water_surface.tga merely affects the colouring of the sea, its size does not have to be changed with other map sizes.
map_FE.tga is the default map shown in the faction selection screen if you don't have an in-game map for a faction
descr_events.txt - can trigger emergence, plague and historic events etc.
descr_mercenaries.txt - controls recruitment of mercenaries
descr_win_conditions.txt - defines victory conditions
descr_disasters.txt - text shown when a natural disaster (eg volcano, earthquake) occurs
descr_regions_and_settlement_name_lookup.txt file not used in later versions of the game.

map_faction.tga's; leader_pic_faction.tga's; and description_faction.txt files simply give the information seen in the faction selection screen