Before you begin making your custom scenario you need to have a think about what the scenario will be about. Then you need to decide what labs to use.

The current labs are
- Disease Lab (used for making custom traits and designing your own disease)
- World Lab (used to edit country populations, climates and even alter plane and boat routes)
- Goverment Actions Lab (used to create custom goverment actions or edit the default ones)
- Events Lab (used to create powerful events, there are lots of ways this could be used)

The type of scenario you are making will alter what labs you'll need.
For example, if you wanted to create the Black Death you would use the Disease Lab so you could make the disease like the black death. If you wanted to make a post apocolyptic scenario, you would use the World Lab so you could alter country populations and climates.

You can use any combination of Labs. You could use them all if you wanted, or you could use only a couple. The more labs you use the more work your scenario will require.

There is also Scenario Data in the Labs menu, however it isn't optional as all scenarios require the scenario data.

Scenario Data is one of the most important labs in the scenario creator, it is essential to getting people to subscribe to and play your scenario. In this section I shall explain what everything does and why it is important.


Scenario Name: Pretty self explainitory, it is the name or your scenario. It is incredibly important to your scenario's success. You need a title that catches the attention of people, something that is popular would have more success compared to something that is unheard of. (That isn't always the case but a majority of the time it is)

Scenario Description: This is the description of the scenario that people will read in the steam workshop or in the actual game when they are browsing the scenarios. If it is the title's job to draw attention, then the desciption has the task of getting people to play the scenario. There are a few ways you could do a description, here are some examples.
1 - Provide a brief but to the point backstory (much faster and generally leaves some mystery)
2 - Provide a long backstory (takes some time but really gets people invested into the story)
3 - Explain Scenario Gameplay (Helps people understand the mechanics of your scenario)
4 - Explain Scenario Gameplay + Provide a Backstory (See 1,2 and 3)

Scenario Icon: Choose an Icon that you will see when view your scenario in the workshop or in the actual game. You can choose one from the game or get a custom one

Private/Public Feedback Email: You can put your email here to get feedback from people who play your scenario on other platforms. If it is public anyone can send you feedback. If it is private then only the developers can send you feedback.

Plague Name: Choose a name for the plague. If you decide to leave this blank, then it will use the last name the player used when playing the base game.

(Disabled if Disease Lab Active) Lock Disease Type: Allows you to pick which diseases may be used and which can't be used. If you are using the disease lab this optional will be unavaliable.

Popup Title/Text: At the start of the game the players will receive two pop-ups that tell them a bit about the scenario before they select their starting location. Here is some information you could tell the player in these pop-ups.
- Backstory
- Explaining Gameplay
- Suggesting Starting Country(ies)
If the text/title is left blank it will use the default in game text.

Set Starting Country: Allows you to pick the starting country as well as the infected and dead percentage of the country (Zombie percentage is also avaible if Necroa Virus is used)
For example, if you set dead percentage to 1 and infected percentage to 3 then at the start of the game, 1% of your starting country will be dead and 3% will be infected.
Setting the infected to another number higher than 0 will make the start of the game faster. Keep that in mind.

(Requires Disease Lab to be Active) Custom Victory Condition: Allows you to make a win when everybody is infected victory condition (Like Neurax Worm Transedence Victory) You can pick the game win trait (Trait that needs to be evolved to allow this Victory) You also edit the end game title and text which is a pop up you recieve before winning the game and the Tagline which is some text that appears after you win (On the Victory Screen)

Scenario Score Adjustment: Increase/Decrease the score you recieve at the end of the game by a percentage (I believe 1 = 100% however there is a slim chance that I am wrong)

Event Restriction: Disables certain events (such as Airplane filters) - Highly recommend if you are using the disease lab. Irrelevant if you set the default events in the event lab.

Gene Selection: Allows player to use their unlocked genes in the scenario. (i.e, ATP boost, darwinist and other things like that)
Turning this off will make your scenario easier to balance.

Allow Cheats: Allows players to use cheats in your scenario assuming they have unlocked cheats. I highly recommend you turn this on while you are in the testing phase, so you can use the ulimited dna cheat to test all your traits.

Custom Start Date: Set the day that the scenario starts on. If you don't set this then every game will start on the same day that it is being played.


Lots of these are very important to your scenario's success so take the time to go through this section for all your scenarios.

In this section I will talk about the stats that you can edit in the disease lab and what they do

First stats are infectivity, severity and lethality, these are the most basic yet most important stats for your disease. We should (hopefully) all know what infectivity, severity and lethality is and what it does. What is important for you as a scenario creator to know is how much to increase them by to keep the game balanced.
Infectivity, Severity and Lethality have a maxium limit of 100. At the start of the game a regular disease would start with 1 for Infectivity and Severity and 0 for Lethality.
I won't tell you what number you should use, instead I shall tell you what number the base game traits have so you have an idea how effective your trait will be.

Infectivity
1 - Anemia, Nausea
2 - Blood 1, Rash, Livestock 1
3 - Bird 1, Rodent 1, Coughing
4 - Air 1, Water 1
5 - Sneezing, Extreme Zoonosis
6 - Bird 2, Rodent 2
7 - Air 2
8 - Water 2, Insect 2, Dysentary
9 - (None that I could find)
10 - Necrosis
11 - Skin Lessions
As you can see 3 is an average for tier 1 transmissions and 7 an average for tier 2 transmissions
The Extreme Transmissions all used 5 (I only include Extreme Zoonosis on this list though)
The symptoms varied from 0, 1, 2 and 3 for tier 1 and 2. Then varied even more from 0 (Coma) to 11 (Skin Lesions) for the higher tier symptoms

Severity
1 - Coughing, Nausea, Rash, Anemia
2 - Cysts, Hyper Sensitivity
3 - Insomnia, Fever
4 - Abcessess, Skin Lessions
5 - Paralysis
6 - Immune Supression
7 - Systematic Infection
15 - Hemorrhagic Shock, Coma, Insanity, Dysentery
20 - Necrosis, Total Organ Failure
As you can see severity rapidly changed from 5's and 7's (Tier 3) to 15's and 20's (Tier 4)
Severity starts pretty low and eventually gets to really high numbers

Lethality
1 - Diarrhoea
2 - Pulmonary Oedema, Pulmonary Fibrosis
3 - Fever
4 - Immune Suppression, Tumors
6 - Systematic Infection
7 - Internal Hemorrhaging
13 - Necrosis
15 - Hemorrhagic Shock
25 - Total Organ Failure
As you can see there is some low lethality from most symptoms with some high lethality from a few certain symptoms. All lethal traits are symptoms that are tier 3 or higher.

Cross Country Transmission

Air, Sea and Land are the three cross-country transmissions. Air increases infection rates by planes, sea by boats and land by spreading to adjacent borders. These increase differently to the previous three stats. You set them in the starting stats area (default is 1 across the board)
but then instead of simply adding to that with set numbers, you add a percentage of the current number.
(If I set Land transmission to 1 in the starting stats and then have a trait that adds 10, it will by 1 x 10 = 10. Then 1 + 10 = 11 making the new land transmission rate 11. If I had a second trait that improved it by 3, it would be 3 x 11 = 33 + 11 = 44. The new land transmission rate would be 44. This is also why fungus has bad cross country transmission even though transmission rate increase is the same for Bird, Air and Water, because fungus starts with 0.0001 transmission rate and instead of adding 9 to 0.0001, it multiplies 0.0001 by 9 and adds the result.)

To summarise, if X equals current air transmission rate and Y equals increase from a symptom.
X x Y = Z which means X + Z = C
C then becomes your new air transmission rate.

Bird, Air and Water increase land, air and sea transmission respectivly.
By Bird, Air and Water 1 all increase their respective transmission rate by 9 and tier 2 by 90.

Corpse Transmission: This allows infected corpses to spread the infection, making it safer to have lethality without everyone infected yet.
Necrosis has 10 corpse transmission
Neurax Worm has two corpse feeder traits that add 5 and 10 respectivly (15 total)

Mutation Chance: This stat affects your chance of recieving a mutation
Virus starts with 2
Default Disease Types start with 0.5
Neurax and Necroa start with 0.01
Most tranmissions that improve mutation chance do so by 0.5 (Tier 1) and 1 (tier 2)

Enviromental Effectivness
This effects your disease ability to spread in different climates including rural, urban, humid, arid, poor, wealthy, cold, hot.
Normally these all start at 1 (0 for wealthy, 0.1 for cold/hot)
Tier One transmissions improve effectivness by 0.8 (except Insect) and 1.2 for Tier 2.
Abilities (Hot, Cold and Drug Resistance) Improve by 0.3 for tier one and 0.6 for tier 2 (0.7 for Drug Resistance)
These are generally improved by 2 over two traits (Poor, Rural, Urban, Arid, Humid) and 1 over two traits (wealthy, cold, hot) these stats are very important for a scenario (try infecting the world without your resistances, I challange you) You should always provide some form of wealthy, cold and heat resistance (unless you set the starting effectivness to 1 for wealthy, cold and hot)

Change to Current Research (CtCR) and Research Inefficiency Multiplier (RIM)
CtCR means there is more work needed to develop a cure (Like a genetic Reshuffle)
RIM slows future research speed (Like Genetic Hardening)
These are both very useful to have in your scenario though not required in all situations
Genetic Reshuffle uses 0.25 for all three tiers
Genetic Hardening use 0.1 for tier one and 0.3 for tier two
Some symptoms use CtCR as well, however they have lower numbers (0.01 for all, some use 0.03 or 0.06. Highest is 0.24 (Coma))

Spores Produced: Sends out Spores to infect another randomly chosen country (Spore Burst from fungus) 1 spore = 1 new country infected. (tip: try not to overload the scenario with spore bursts unless it makes sense to have them)

Well that is it for this section, there were things I didn't include in this section (Such as Starting Trait, Pre-Load, Body Scanner and Increase Speed) because I thought they would fit in a different section.

When you look around the workshop you will undoubtably find scenarios with custom images, and if you play some of them you'll find custom trait icons as well. Do you wish to do this as well? Allow me to give you the step by step process.

You'll need to go to http://image.online-convert.com/convert-to-png and follow the instructions there to have an image converted.

You must copy the url of the desired image and paste it where the online converter tells you.
Before you convert the image make sure to change the size of the image in the 'optional settings' to either
- 184 pixels x 184 pixels (For news pop-ups and scenario images)
- 78 pixels x 78 pixels (For trait icons)

Edit: Using the snipping tool to save an image you see online works as well!

The image will be converted and you'll be given the option to save it, do so. The saved and converted image will be in your files, I'd recomend moving it somewhere easy to find.
I myself made a folder named 'Plague Icons' and have all of my converted images go there.

Next you'll have to go into your custom scenario and find a green box with an arrow inside. This green box with the arrow is located next to anything that has an image you can upload.
Click on the green box and you'll see a bunch of files pop up, search for your saved image and double click it, or click it once than press ok.

Now you should (hopefully) know how to put custom images into your custom scenarios, if you have any questions please leave them for me in the comments section

This section was made to answer Dragonborn's question

'Can you override the default pop-ups for the cure?'

The answer is yes and it is quite easy to do so. When you open the events lab for the first time you'll recieve a pop-up about the default events you want to allow, you want to untick 'General Narrative'

The next step is to create an event, select the variable global condition and find something like 'Cure begins' or 'Cure Complete' and then on the right side of expression you'll want to select TRUE.

Next you must create an outcome, select the news pop-up outcome and type in your own message.
And you should have successfully created your own message for when the cure begins, or is completed or whatever it is you want.

I hope this helps and thanks to Dragonborn for the question.