Create an event, add the command Control Variables on it and select a blank variable (You can add it an easy to recognize name like 'random_chance').



Go to Operand and select Random. Here you'll have to insert two values: The left one is the value that would cause the random event to occur, and the right one is the total value that will be counted, just like a dice roll.

• 1 ~ 100 would be 1% of chance.
  
• 1 ~ 20 would be 5% of chance.
  
  And so.

Now click on 'Accept' and in the very same event insert a Conditional Branch command.

Select Variable and make it 'Equal to 1'.



Now whatever command you add to the Conditional Branch will only occur if it gets to value 1.



You can additionally add something to the 'Else' section if you want something else to happen when the "dice roll" fails.

There's various possible triggers for an event, and the Random Event will occur differently depending on the trigger you have selected.

Let's go one by one.

• Action Button: The 'dice roll' will occur every time you press the action button in range of the event.
  
  
• Player Touch: The 'dice roll' will occur every time the player simply touches the event.
  
  If the Event Priority is 'Below character', the 'dice roll' will occur when the player steps over the very same tile that the event is in. If the Event Priority is 'Same as character', the 'dice roll' will occur when the player touches the event while being in one of its surrounding tiles.
  
  
• Event Touch: The very same, but with an event instead of the player.
  
  
• Parallel Process: The 'dice' will be actively being 'rolled' every frame.
  
  This one's problematic. The 'dice roll' being eternally active means that even a heavily low chance command can frequently occur; however there's a few workarounds to this, just like adding a Wait command to the event (If you want your 'dice' to be 'rolled' every second instead of every frame, add a Wait command of 60 frames, which will be 1 second).
  
  
• Autorun: This is similar to 'Parallel Process', but this 'dice roll' won't let you keep playing as it will take over the game's processing.