Emergent Factions - M2TW

General Information

In the vanilla Medieval II - Total War game, two factions (the Mongols and the Timurids) emerge after the start of the game. There are some similarities between the mechanism used to do this and the way the Slavs emerge in Barbarian Invasion - see here for description of that, however there are a number of important differences.

The most important and useful difference is that in M2TW a faction can be made to emerge in a region which is in the middle of the map, simply use it's internal region name in the emergence trigger. (In BI only regions that bordered the edge of the map could be used)

When and where the Mongols and Timurids enter the game is controlled within the campaign_script.txt file and the descr_events.txt file.
A randomly timed warning event is included in the descr_events.txt file

; ------------ CORE GAME EVENT --------------
event	historic	mongols_invasion_warn
date	128 144

that event triggers a new event in the campaign script

;-- Mongols invasions --
monitor_event EventCounter EventCounterType mongols_invasion_warn
and EventCounter > 0
; ADD SCOUTING INVASION
add_events
event	counter	mongols_invasion
date	4 8
end_add_events
if I_EventCounter mongols_invasion_warn == 2
terminate_monitor
end_if
end_monitor

the counter related to that then triggers the emergence in the next piece of script.

Making Other Factions Emerge

Factions other than the Mongols and Timurids can be made to emerge in M2TW, to do so they must be included in descr_strat.txt without settlements, armies or family trees; all that is required there is similar entry to Mongols eg:

faction	mongols, balanced henry
ai_label	default 
dead_until_resurrected
denari	10000
denari_kings_purse	3000

Note they must have the 'dead_until_resurrected' line in their faction section. Their faction name should be placed in the non-playable section at the top of the descr_strat file.

They must also have similar entry to Mongols in descr_sm_factions.txt

faction						mongols, spawned_on_event
culture						middle_eastern
religion					islam
........
custom_battle_availability	yes
horde_min_units				10
horde_max_units				20
horde_max_units_reduction_every_horde 10
horde_unit_per_settlement_population	250
horde_min_named_characters	2
horde_max_percent_army_stack 80
horde_disband_percent_on_settlement_capture	0
horde_unit					Mongol Infantry
horde_unit					Mongol Foot Archers
horde_unit					Mongol Heavy Archers
horde_unit					Mongol Heavy Lancers
can_sap						yes
prefers_naval_invasions		no
can_have_princess			no
has_family_tree				yes

the relevant sections needed are marked in bold. Unlike BI the units used, Mongol Infantry etc, do not have to be separately defined as 'horde_units', any units the faction has ownership of can be used.

The time and place of emergence has to be triggered either by descr_events.txt or the campaign_script.txt.

Triggering Emergence from descr_events.txt only

The easiest way to trigger emergence of a new faction is to use descr_events.txt directly to trigger the emergence. This does not provide as many options for applying randomisation and conditions as triggering from the campaign_script would, but is nice and easy to do.

Make sure faction is dead_until_resurrected in descr_strat.txt and has the hording entries in descr_sm_factions.txt. Then simply add to the descr_events.txt in your campaign folder:

event	emergent_faction	scotland
date	2 5
region 	London_Province

or similar - that example makes Scotland emerge at random date between years 2 & 5 in the London_Province
(where London_Province is the region name for the area you want them to emerge in).

You also need to alter the historic_events.txt.strings.bin file in data/text to include an event message for their emergence - if you miss this stage game will CTD when the emergence event is triggered.

Use Alpaca's .strings.bin converter to generate text file and add appropriate TITLE and BODY lines for your faction, e.g.:

{THE_SCOTLAND_EMERGE_BODY}    Blah, blah......
{THE_SCOTLAND_EMERGE_TITLE}   Scotland Invade!

to historic_events.txt delete the old historic.events.txt.strings.bin and a new version will be generated when you run the game containing the added lines.