From The Battle for Wesnoth Wiki
The [modification] toplevel tag
Template:DevFeature1.11 This tag describes a multiplayer modification. A modification is practically a bunch of events which get included into the scenario if the modification is enabled.
The following keys/tags are recognized for [modification]:
- id: identifier for the modification. Must be unique.
- name: the name of the modification, as displayed to the user.
- description: a brief description for the modification.
- allow_scenario: a list of scenario ids. Only the scenarios with matching ids will be allowed to be played with this modification.
- disallow_scenario: a list of scenario ids. Only the scenarios with matching ids will not be allowed to be played with this modification. Cannot be used in parallel with allow_scenario.
- allow_era: same as allow_scenario, but for eras.
- disallow_era: same as disallow_scenario, but for eras. Can't be used with allow_era.
- allow_modification: same as allow_scenario, but for modifications.
- disallow_modification: same as disallow_scenario, but for modifications. Can't be used with allow_modification.
- ignore_incompatible_scenario: a list of scenario ids. The scenarios with matching ids will be considered compatible with this modification regardless their dependencies.
- ignore_incompatible_era: same as ignore_incompatible_scenario, but for eras.
- ignore_incompatible_modification: same as ignore_incompatible_scenario, but for modifications.
- require_modification: a boolean value; if set to yes, all players have to have this modification installed to join the game. Default no.
- [event]: any [event] children written inside the [modification] tag will get included into scenarios that are played with this modification enabled. See EventWML.
- [options]: custom options. See OptionWML for details.