Randomness, you KNOW there is a (or several) nasties in the for-coming area, a big issue is that you know WHERE and WHEN they will pop out. Make it so there are a possible 10 spots A creature could pop out. But each has a 50% chance of doing so. So it's possible nothing happens OR that several come out quickly.
If nothing happens - a player is shitting them-self because they don't know what is out there or when, 2 - if all 10 pop out then a player has a massive fight on their hands which will keep the blood pumping.
It also adds replay value. I should also mention that this chance changes if you reload.
If nothing happens - a player is shitting them-self because they don't know what is out there or when, 2 - if all 10 pop out then a player has a massive fight on their hands which will keep the blood pumping.
It also adds replay value. I should also mention that this chance changes if you reload.