Mission Editor tips¶

Trigger actions of the DCS Mission Editor that VMCT does not wrap, and that are worth knowing. You set them by hand in the editor, in a VMCT mission as in any other: the build keeps the triggers you wrote.

Each tip says where what it states comes from. Read: found in the editor's Lua files DCS ships in the clear (MissionEditor/modules/me_trigrules.lua, DCS 2.9.30); what the action really does is coded in the engine, so it is inferred from its parameters. Measured: seen in game, with the date.

What VMCT already does¶

Before setting a trigger, check that VMCT does not do it already:

Need	In VMCT
Enforce labels, the F10 view, external views…	`mission.forced_options` — see the reference
A make-believe artillery barrage on a zone	the `-shell`, `-cesar` and `-flak` shortcuts — see the aliases
Mute DCS's ATC	`mission.silence_atc_on_all_airbases`
A smoke screen that blinds the AI	does not exist: measured 2026-10-08, smoke does not keep the AI from seeing and firing
Remove the trees of a zone (SCENERY REMOVE OBJECTS ZONE)	does not work: measured 2026-10-12, the forest stays

A failure on demand¶

SET FAILURE (a_set_failure) causes a failure on the player's aircraft. Read: three parameters, the failure, a probability from 1 to 100 % and a random delay « Within (mm) » in minutes. The list of failures is the one of the player aircraft selected in the editor when you set the action: a mission with several aircraft types can only aim at one type's failures at a time.

Typical use, for training: an F10 menu entry (RADIO ITEM ADD FOR GROUP) that raises a flag, and a FLAG IS TRUE → SET FAILURE trigger. The instructor causes the failure when the student is ready.

A group only the game master commands¶

GROUP CONTROL GAMEMASTER ONLY (a_group_controllable_off) keeps a group for the game master; GROUP CONTROL DEFAULT (a_group_controllable_on) gives it back to everyone. Read: a single parameter, the group. Useful for an opposing force played by a Combined Arms game master, that JTACs and tactical commanders must not be able to drive. Game master slots are opened with mission.ground_control (see the reference).

Animate an object¶

PLAY ARGUMENT (a_play_argument) plays an animation of a 3D model, unit or static. Read: the model's argument number (0 to 1000), a start position, an end position and a speed. Examples: open a hangar's doors when an aircraft arrives, raise a barrier. The argument number depends on the model; DCS's Model Viewer shows it.

Change the briefing mid-mission¶

SET BRIEFING (a_set_briefing) replaces a coalition's briefing during the mission. Read: the coalition, a picture and a text. Useful for an operation in several phases: the phase 2 briefing shows once phase 1 is done, for the players who join along the way.

Grow a zone¶

(dev) ZONE_INCREMENT_SIZE (a_zone_increment_resize) grows or shrinks a trigger zone. Read: the zone and a number of metres, from -100 000 to 100 000. The editor offers it despite its « (dev) » label. Not seen in game yet: check it before relying on it (a front that moves, a no-go zone that spreads).

Destroy a zone's scenery¶

SCENERY DESTRUCTION ZONE (a_scenery_destruction_zone) destroys the map objects in a zone. Read: the zone and a destruction level from 0 to 100 %. Example: a town already bombed when the mission starts. Not seen in game yet; its neighbour SCENERY REMOVE OBJECTS ZONE removes nothing (see the table above), so check it before building a mission on it.