Unless you've played RPGs on a regular basis, you may not have experienced all of these or any similar form, but you might agree with me, these are pretty easy circumstances in which to fall victim. Some of these are text based and the rest are from PC games. One scenario would happen in a game I develop (which hasn't happened yet, but oh well). If you're the first to guess which one, I'll send you a free copy of Snow Leopard.
1. You fire your cross bow at a huge skeleton. The arrow flies through the air and darts between the two lower bones of his rib cage, missing the skeleton entirely, and striking the wall behind it. You have no other weapons.
2. You fall down a well. The only "obvious" exit is dragon
You exit dragon
3. You cast a 30-yard range fire storm at a goblin, killing him instantly, but wasting 20 seconds of fire damage on no apparent enemies within a 30-yard radius. After the spell dies out and while it recharges (which takes another 20 seconds), twenty Whiptail Devourers spring from the soil.
4. You stumble upon a trap door. After close inspection, something tells you, it doesn't REALLY look like a trap door, does it?
You open door
5. Before going inside to negotiate with the giant Cyclops, you say to your fighter friend, "Don't worry, I have a high charisma attribute."
6. Your new friend says, "Nothing bad is going to happen. I'm friends with the DM."
You follow new friend
7. You enter into combat with a giant crocodile. It is unusual this creature hasn't gone down yet and you're about to die. You look at your weapon. It is not wielded. You are fighting with your bare hands!
8. You didn't bother to read the room description when you entered the sewer, so you are unaware of the high concentration of methane gas all around you. It is dark.
You light torch
9. In an angry tirade, you tell an Admin to go screw themselves.
10. Every potion you'd ever had identified turned out to be a healing potion. You are bleeding, but you find yet another unidentified bottle of potion. Why pay a spell caster to identify it? It will still work without being identified.
You drink potion
*Note: Unidentified POISON will still work, too!