[GUIDE] Mission Creation for MSFS

This guide is from the FSDeveloper Wiki:

Mission Creation for MSFS

Feel free to suggest changes and additions!


Creating a mission is a complex task involving a diverse use of tools & skills. Getting your first mission going is likely to cause you some headaches.

Still here? Good. Once you do have that first one running, the sky’s your limit. That basic set of rules and files that make up a mission are always the same so once you’ve got those sorted, it’s just a case of coming up with an idea and writing it.

At it’s simplest, a mission is just a scripted set of events that tell some kind of story. It may be dramatic - mountain rescue, failing aircraft, poor weather. It could just as easily be a simple flight from A to B with you pointing out areas of interest along the way, or a completely abstract challenge like finding out how many times you can touch-and-go in a 747 in five minutes.

Technically speaking, there are two main classes of things in a mission; Actions and Triggers. An Action makes something happen, and a Trigger checks to see if something’s happened and calls an Action if it has. By stringing together Actions and Triggers, you tell your story.

You’ll also need to prepare the conditions of your flight; what will be the plane, time, location, route, and weather of your mission? Are there other planes flying around or parked on the airport? And how much assistance will you give the player?

Lastly, your mission will need sound files for the mission speech and some text and images for the briefing, loading, and ending screens.


1. Come up with a basic storyline

The first step of creating a mission is coming up with a scenario and story. You can make a tutorial, emergency scenario, even a treasure hunt, but you will need to think of a mission progression. What is the start of the mission? What will you need to tell the player and what will they have to find out on their own? What are the possible ways to complete the mission? Are there branching paths? And of course, how will the mission end? Will the player receive a grade or reward?

It can help to have a written structure. Think of it as a screenplay, and follow the same three-stage layout.

The first section is your introduction. You need to get the player’s interest, explain who they are and why they’re there. You use the first bit to get everything set up so that when The Exciting Thing happens, they know why and what to do about it.

In part two, The Exciting Thing happens. It doesn’t matter what it is, but assuming you have some kind of event to which the player is supposed to react, this part details what happens. Once they’ve managed to cope with the situation and get it under control, they move on to…

Part three, the conclusion. Having successfully dealt with the engine fire/squalling brats in the back seats/condor-strike, the player gets to reflect on what they’ve done and enjoy the feeling of success for a little while. You could always throw in a last-minute plot twist of course.

Structuring like this gives you a tidy way of making your mission appear much more complex. You can easily provide different threads, or ways of achieving something, without too much extra effort. Let’s say your Introduction sees the player getting from a bush strip to the head of a particular valley. You start with them following the river, simple enough. Later on, you could add the option to fly across the peaks and save time; as long as they reach the same head of the same valley, the rest of the mission isn’t affected. If they’ve tried the mission before and failed, chances are they’ll decide to try shortcuts anyway. Wouldn’t it feel better if, having decided to cross the ridge instead of fly round, the mission reacts to that by saying “Hey, you’re going over the ridge! A bit risky in this weather but the views will be stunning”? You can issue different Rewards, or maybe even alter how the next section plays out, depending on the path they took.

In short, you can see your mission sections as leading up to choke-points, such as the head of the valley. If you have three sections, each with three different ways of achieving it, that’s nine different ways of flying a single mission.

2. Turn your story into a mission

Now comes the longest, and hopefully the most fun part; turning your idea into an immersive mission.

First, you have to clearly define the flow of the mission. You may find it easier to have a big sheet of paper and draw the mission out in pencil before you start coding. That lets you work out how it fits together logically without having to worry about whether or not you’ve got the spelling right.

For example, you know that after you take off you want to have some speech, and then there are three ways of getting from A to B, where the next section starts. OK, so that’s three boxes to draw; ‘Takeoff’, ‘Speech’ and ‘At point B’. The speech should happen 30 seconds after takeoff, so note that down next to the Speech box. Then you can draw three lines between ‘Speech’ and ‘At Point B’ to show the three paths, and the first thing to do on each path is disable the other two paths.

Already you’ve got a decent map of what happens in what order, and translating from these into actual mission-system code will be easier.

Read the list of possible Actions and Triggers, to find out what kinds of things you can check for and do. Try and spot a likely match for each of the boxes on your sheet of paper.

To keep the example going, you might have a PropertyTrigger checking “Altitude AGL > 10” to test for takeoff. That would start a 30-second TimerTrigger using an ObjectActivationAction which, in turn, would call a DialogAction for your “Speech” box. You would need one Trigger per potential path; they might be set to detect altitude, or heading, or more likely that the player has entered an area. Each of those would need another DialogAction (just to keep the player informed), an ObjectActivationAction to enable the Trigger that checks “At Point B” and another ObjectActivationAction to disable the other two paths.

3. Create a mission project

3.1 Using the SimpleMission sample project

You can als use the SimpleMission sample project. Download it and complete step 1 and 2 of the guide.

3.2 Manual

You can create a mission project with the MSFS devmode. You can enable the devmode in General Settings>Developers.

To create a new mission project, click [DevMode] > New project > Select location and name > select custom > Add a display title, package name, and select content type MISSION > Set the asset type to Mission and name it MissionName-Mission > create.

4. Decide on flight conditions

Next, you will have to configure the flight conditions. To start, you can create a flight plan in the worldmap or with Little Navmap. This flight plan will be shown to the player when the mission starts, so it shouldn’t spoil the unexpected parts of the flight (e.g., an emergency).

Then you decide on the starting point of the mission (e.g., at the beginning of the flight or in the air somewhere along the route).

4.1 Create the flight file

To create the flight file, load the flightplan and select the desired starting location in the worldmap. Now choose the aircraft, livery, fuel, payload, and atc options. Then choose the time, weather preset, and the multiplayer and traffic settings. Load the flight. Set up the aircraft how you want it (lights, switches, autopilot, etc.). You can customize the weather and save it as a preset. Lastly, locate the plane exactly where you want it, with the correct speed and trim settings. Then click ESC to pause the game and then SPACE to save the flight as a .FLT. Move the flight file and flightplan to the mission project.

You will need to manually edit the .FLT to choose the assistance preset, mission category, traffic, briefing and loading screen. You can use the .FLT in the SimpleMission project as a reference.

Add pictures

Lastly, you will have to add pictures for the mission thumbnail, and the loading, briefing, and ending screens. The names for the loading an briefing pictures are defined in the .FLT file. The thumbnail will need to be named: Activity_Widget.jpg and the endscreen picture will need to be named: rewardscreen.jpg. You can use the pictures in the SimpleMission project as a reference.

4.2 Define custom weather

You can customize the weather with the weather panel during flight. Save it as a new preset. You can find the .WPR file in \AppData\Roaming\Microsoft Flight Simulator\Weather\Presets\. Move it next to the .flt file and rename it to Weather.WPR. You can fine-tune the weather by editing the .WPR file in Notepad++. You can use the .WPR in the SimpleMission project as a reference.

5. Set up a mission script

You can set up a mission script in two ways:

5.1 Using the SimpleMission sample project

The SimpleMission sample project contains an .xml you can use as a starting point. Download it and complete step 3 of the guide.

5.2 Manual

The mission script defines everything that happens after spawn.

There are some basic parts to each mission that you will have to define first.

5.2.1 Mission type

There are different mission types to choose from. You need to add one of them to your script, to enable the mission ending. The mission will end when all active objectives have been completed. Each objective in the mission is connected with a corresponding goal, the state of which can be Pending, Completed, Failed, and Aborted. If all active objectives are marked as completed, the mission will end in success.

5.2.2 Flowstates

MSFS introduced flowstates, which determine the flight state, and flowevents, which control sim-level actions (e.g., pausing the sim, show startup info, disabling the ATC panel).

You should add an intro with a FlowStateAction.

6. Coding your mission

Now you will turn your mission diagram from step 3 into a mission script. For this you can use the Devmode and the script editor.

6.1 Script Building Blocks

The script is mostly made up of a few building blocks:

6.1.1 Triggers & Actions

The basic parts of a mission script are triggers and actions. When a trigger ‘fires’, it can start different actions and activate other triggers. A bunch of these together makes up a basic mission.

6.1.2 Mission objects

Mission elements define a range of things like mission type, goals, world traffic, camera, and thermals.

6.1.3 Calculators

You can use calculators for more advanced logic in your mission. It can take in multiple variables and trigger different actions based on a logic. You can also use this to calculate a mission score and probably many more applications which you can explore.

For a complete overview of elements, see MSFS Script

6.2 Testing and editing mission

To test the mission, build the project and copy the contents of the ProjectFolder\Packages\ folder to the Community folder.

Keep DevMode enabled and make sure Options > World Objects is enabled, to see the areas.

You can start the mission by going to the home screen, then select Activities > Custom Content > Your mission.

With the script editor open you can see if the objects are loaded in the mission. If the names are white, they are loaded, but if they are red it means they are not loaded. While working on your mission, you can update the objects by clicking Script Editor > Game > Update.

With the Developer Camera enabled you can double click on the objects in the script editor and the camera will go to their location.

Go to Script Editor > View > Gizmo to get a gizmo with which you can move objects that have a world position.

6.3 Debugging mission

The MSFS script editor isn't good at debugging your mission, so you will have to test the mission and try to create it in a standardized way.

It is good practice to have all triggers except the first disabled, so they can’t be triggered before they’re supposed to. You should use ObjectActivationActions to enable triggers at the appropriate time. You can use the script editor to look for breaks in your mission logic. All objects that aren’t referenced by another object are marked with a white dot:

Script editor example

For actions this means they will never execute. For triggers this means they will either be active from the beginning or they will always be disabled.

6.4 Compiling the mission

To compile the mission for export, click Clean All, then Build All, Make sure there are no errors in the console from the building process. Then click Build & Export, ensure the mission package is checkmarked, choose Community Publishing, and select the Export Directory.

Other reading

Mission Creation - The Basics

FSX Mission Building Tips by Paul Lange:

[PDF] Part 1 (On the process of mission creation)

[PDF] Part 2 (On the SDK, a bit outdated)

Feel free to reply with your knowledge and tips, so I can make the guide better and more complete.


Thank you. I am really grateful to you, as I realized that nothing new has been invented by Asobo, and the missions are quite repeatable. That is, with triggers and promotions and POIs, I’ll figure it out. But I read this guide carefully, and went to the Wiki, but I never found the most important thing - the first steps.
Take your mission in Telluride (by the way, in SU7 I never saw a limousine in the parking lot, although it is in the assets). I created a flight plan, entered it into CJ4, saved the flight at approximately the point where the original Lear45 was. I have a bgl with the limo next to it on the disk. I can even easily unzip the original SPB mission and put it next to it. What’s next??? Start the simulator, load in Telluride, in DEVMODE select “New Project”…

This is where there is no information at all. I would like to read how to combine and compile it all. The working process of creating and editing “building blocks” is familiar to me.

Hey, I just updated the guide. Now it is more of an actual guide that leads you through the process of mission creation for msfs. All the old content, as well as this guide, can be found on the FSDeveloper wiki. Please tell me if something is not clear or not the best way to do something. Of course also feel free to contribute to the wiki. Good luck with your missions!

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Thank you MrLiamTim for your efforts. Much appreciated!

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