How can I properly measure "ingame" time to make a countdown? I'll explain it with an example:
The party encounters a small ghost ship, and they board it to investigate/salvage. When they get to the bridge, a video starts playing in the main screen, saying that they're all going to die, and that the ship is going self-destruct in 30 seconds. The party has now to make a narrow escape or suffer the consequences.
Now, I don't want to kill my friends right away, but I want them to feel anxious to escape the vessel as fast as they can, but how can I measure how fast they can go, how much time do they have left? They'd be like "ok, we run and get away safely".
In combat I do believe each round is roughly 5 seconds… I could add combat and penalize their escape time for each round, but what about non-combat? And don't tell me it's up to me as a GM, I already know that, but I want the players to feel they're running out of time, to quantify how long does them take to do something before the time runs out, so they have to "hurry".