UML Activity diagram how to show game ends when time has passed?

Question

When 20 seconds passes, the player unlocks poison. Poison can be dropped to slow down the enemy, or the player can accidentally eat his own poison and slow down.

I want to show that the player wins after 60 seconds has passed. I thought I would show it as a loop looping the 20seconds 3 times but that would be incorrect because the player can only unlock the poison once.

Would the best way of showing this be to draw a rectangle around the entire diagram and just state (after 60 seconds, player wins)? - and have it lead to an end circle?

Answer 1

Rather than polling for the timer you can show timers and an interrupt using a Interruptible Regions like this:

The 20 seconds timer to the left will hit after 20 seconds when the region has been entered. It will continue with any arbitrary action (here Unlock potion).

All actions within the region (the dashed box) can experience also an exception that will transfer the flow to the Timeout after 60 seconds. If needed you could mix actions that will not be hit by the timer outside the region.