Features of Rome: Total War's Different Game Engines

This article is about difference between 3 engines of Rome - Total War. List here still incomplete, please improving it if anyone know something more about them.

Three engines of Rome - Total War are..

- Vanilla engine (1.5/1.5.1)

- Barbarian Invasion engine (1.6/1.6.1)

- Alexander engine (1.9/1.9.1)

Common Features in all 3 Engines

Modder could use these features which considered as free updated for RTW in all latest updated.

- transition screen logo position in descr_transition_screen.txt (not use in vanilla but feature is permisable and use since release of BI)

- religion feature (requires descr_belief.txt which not exist in vanilla data folder but feature could be used with vanilla and Alexander exe)

- loyalty feature (requires shadow faction setting in descr_sm_factions.txt and "rebelling_characters_active" in descr_strat.txt)

- Swimming units

- Recruitable generals

- Senate features (could be using in 1.6 and 1.9 if superfaction is activate)

 -> superfaction (requires setting in descr_strat.txt)
 -> senate tab (requires roman cultures and faction names romans_julii, romans_brutii, and romans_scipii)
 -> senate mission (requires superfactions and faction must be part of superfaction and list as first 3 factions in descr_sm_factions.txt)

- Some Barbarian Invasion features in campaign (requires "options bi" in descr_strat.txt)

 -> Some sparkling effect when unit gain exp in battle
 -> Allow rename settlement on strat map
 -> disable display unit ability and put description of unit on first paragraph on unit browser
 -> Prevent AI from winning when it fulfilled winning condition
 -> option to enable night battle (requires "options bi" and "night_battles_enabled" in descr_strat.txt)
 -> option to disable marian reforms (requires "marian_reforms_disabled" in descr_strat.txt)
 -> option to disable gladiatorial uprising (requires "gladiator_uprising_disabled" in descr_strat.txt)
 -> Re-emergence setting for faction to able to coming back after its last character dead on strat map (mostly by loyalty rebellion).

- "options +defeat_movie_bi_style" in descr_strat.txt

Barbarian Invasion Engine (1.6 and 1.6.1) only

These features are only available in game version 1.6 and 1.61

- unit shieldwall and schiltrom formations (access through export_descr_units.txt)

- horde feature (require horde units in export_descr_units.txt and setting in descr_sm_factions.txt)

- barbarian invasion's campaign hardcoded (requires "options bi" in descr_strat.txt)

 -> emerging factions as horde on the edge of the map by event (setting in descr_events.txt in campaign's folder)
 -> emerging factions by rebellion (setting in descr_sm_factions.txt)
 -> romano-british emerging faction (require faction name romano_british, and region name Britannia_Superior)
 -> special event message for declaration of new faction leader and new heir for empire_east and empire_west factions

- steam version of Barbarian Invasion engine (1.6.1) could not run normally without using of steam launcher, if try to launch exe file outside steam launcher, it would load vanilla engine (1.5.1) instead. There is process to circumvent this but it consider as mess up with game folder.

Note: shieldwall, schiltrom, and horde feature in export_descr_units.txt recognized by vanilla and Alexander engines but content would be ignore as features are locked to not use.

Alexander Engine (1.9 and 1.91) only

These features are only available in game version 1.9 and 1.9.1

- additionally requires file chat_filter.san in data folder

- alexander's only features (disable by run "-noalexander" command line functions)

 -> generally it is option which to make engine run vanilla rome total war on alexander engine
 -> mod that run without this option would have alexander\data folder as primary folder (with exception on content in index files and pack files which would still looking into vanilla data folder), thus requires to use -noalexander for mod which not completely overhauled.
 -> mod that run with "-noalexander" command line functions require additional "data\world\maps\campaign\Battlefields" folder and its content in order for custom battles to work.

- senate bonus disable when player play as senate faction (normally senate faction get 10000 dinarii per region it own if it end turn with money less than 0)

- allow customized game intro video (through descr_fmv.txt)

- Hardcoded limit of descr_model_battle.txt has been lift from 250 to ???

- Custom "portrait", "strat_model", "battle_model" for character spawning/creation in descr_strat.txt, descr_battle.txt or in character spawning script

- additional inside files' alexander only feature

 -> "alternate_ambush_defender_deployment" purpose flag in descr_formations_ai.txt
 -> two new additional battle commands for scripting, "unit_group_automate_defend_position" in battle of Granicus's script and "unit_group_automate_attack" in script for battle of Guagamela
 -> faction restriction for mercenaries types in descr_mercenaries.txt
 -> "show_date_as_turns_remaining" indescr_strat.txt
 -> "ai_do_not_attack_faction" condition in descr_strat.txt
 -> "siege_equipment" condition for character/army creation (modification of siege point cost of siege option)
 -> additional "survivor" condition in descr_win_conditions.txt and option to run script after victory condition is fulfilled.
 -> "Immortality" hardcoded trait which prevent character die from old age

- Total war camera mode bug which camera push screen off the battle and glitch during deployment phase (not feature but is exceptional bug for Alexander engine which generally consider as less bug-prone than other engine)