Set variable
The "Set variable" block allows you to set a particular value to a variable.
This value can be any kind of plain text but also Javascript code.
It means you can apply operations on existing variables:
{{Score}} + 5
{{Score}} * {{Multiplier}}
But also set the variable to the current date for example:
new Date()
Or a random ID:
Math.round(Math.random() * 1000000)