It's the difference between feeling the sword's edge at your throat and the annoyance of a paper cut on your finger. What is it that makes something challenging rather than annoying in a video game?

In truth, most games do contain a bit of both; however, most people will agree that challenge -- not annoyance -- is what they want in a game, and it's important to recognize what differentiates them.

Through the dozens and dozens of games I've played, I think I've come up with a good way of spotting the difference.

Lets ask ourselves a few questions: First, does this task require an inordinate amount of time to accomplish? Or does it instead use up an unusual amount of your precious resources, such as bullets or healing of some sort? Second, would you say the task is trivial or not actually terribly difficult to accomplish at all?

If the game satisfies both of these conditions, then you have something that is genuinely annoying. While the first condition merely makes something challenging -- say like fighting the Tank in Left 4 Dead on expert where it eats up a quarter of your party's ammunition and maybe a medkit or two -- the second condition is what is essential to make for a genuinely annoying situation. Let me give you the best example I can think of from a recent game....

The final fight with Darth Vader in Star Wars: The Force Unleashed 2. I went into this battle expecting something epic. Vader is supposed to be one of the most powerful Force user ever to exist in a galaxy far, far away. He was gifted with amazing powers and was supposedly intelligent as well as a decent combatant; however, this was not the sith I was looking for....

I was instead confronted with a cowardly bullet...er...lightsaber sponge. This fight was not dificult in the slightest. Vader would walk around like a bad ass as usual, but then would drop his guard for no apparent reason and let me attack him a half dozen times.

After lowering his health by one percent by hitting him multiple times with a beam of raw energy that can cut nearly anything it touches, we would enter an almost epic clash...if it weren't for the fact he felt the need to discuss the situation for about a minute before I could resume playing the game.

After a bit of this, he would run away, summon some useless clones, almost throw a giant glass jar at me (although, I'd always slice to him before he could throw it since he can't seem to aim and toss with any speed in his old age), and we'd do the dance again and again.

Once I brought him down to a quarter of his initial health, I really started getting annoyed. I had to spam a button for 20 seconds or so as the final blow...a quick-time event, which was just me zapping him with lightning the entire time. Needless to say the most emotion I felt aside from annoyance was relief when the fight was finally over.

There was absolutely no challenge at all in this fight. Damaging Vader was very easy, and I received almost no damage myself, and I easily replenished my health by killing the pathetically weak summoned goons. It also did nothing but waste time because the developers gave the man a health bar the size of a star destroyer, made him spout minute long dialog intermittently when we fought (I couldn't even play the game while he was talking -- how polite of Starkiller), and then removed whatever spine he had left so that he ran away like ewoks from an AT-ST.

Annoyance is found in nearly all games, though: For example, Fable 3 not having a repair-all button for your owned property, thus forcing you to go through individually and repair each one; and Call of Duty: Black Ops (and most other first-person shooters with level systems) crippling players who have just started out in multiplayer. Even achievements for most games feature one or two that are just plain annoying.

On the other hand, A challenge is something that requires a player to have skill in order to accomplish. It doesn't matter if that skill is the ability to press a button quickly or to come up with a strategic way to place their squad mates on a map. It doesn't matter if the skill is physical or strictly mental -- all that matters is that without that skill, which the player has honed into a fine tool, the task cannot be done.

A good example of a challenge can be found in the Thief series. Thief requires the player to be aloof and use his eyes and ears to their fullest abilities, as those who do not will find themselves at the heavy end of a war hammer or maybe crushed by a half ton boulder. Thief also requires that the player intelligently manage the few precious resources they have in their tool belt because no one wants to get caught in a room full of zombies without holy water or water arrows on hand. Thief requires these and many other skills of the player to truly succeed, especially in the first two games where the expert level of difficulty doesn't allow you to kill any human targets.

If the task cannot be done by a monkey bashing the controller buttons or by your (not tech savvy) grandmother, then chances are you have something that can be considered challenging.

Can you remember games that have annoyed you to the point you wanted to just put them down and not bother? What games have you found that have tested your skills to their very limits? What's the difference between annoyance and challenge for you, and can you enjoy games that annoy you?