The games that contain this mechanic are varied, and include classics such as the Super Smash Bros. series and God of War, as well as current titles like the upcoming Prince of Persia reboot and Team Fortress 2. Regardless of explanation (when there is one), there is absolutely no good reason to keep including the double-jump in games. The most obvious rebuttal: why not just allow for higher jumps? If the point of the double-jump is to allow players access to higher levels of terrain, then why not just design a variable-height jump, controlled by depressing the jump button for variable lengths of duration? Tap: a simple shallow jump. Tap and hold: a much higher/longer jump. It's definitely more challenging to master, and thus more rewarding when accomplished. But it's rarely used, and this is a great example of laziness in design, and worse, a catering to perceived appeal.

Let's face it: it can be tough to create and market a new video game these days. The risk of innovation is only manageable either when huge companies with money to burn are involved, or when tiny indie developers bite the bullet and work for the love of it, just to get their crazy ideas out there into the world. Those development studios that fall in between these extremes often take the tack of basing their game on the tried-and-true formulas of past successes -- the first-person shooter, the role-playing game, the matching puzzle. With games like these, the audience pretty much knows what to expect, so if they've liked Familiar Game X, then they'll also probably like New Game Y if it plays similarly to Game X. Thus are conventions born and nurtured.

But in the desire for profitability, the overused conventions are simply aped without being upgraded, leading to a feeling of "been here, done this", regardless of how amazing the game's graphics are, or what the overarching storyline might be. Ergo: the double-jump.

What's particularly troublesome about the double-jump is that it gives players a cheap way to cover their mistakes. Did you mis-time your jump? Just jump again in mid-air! There are other arbitrary tropes as well: the ubiquitous health pack in first-person shooters, the availability of weapons and ammunition just lying around in destructible crates, and the hallowed Continue option. If it's possible to lock down a single reason for inclusion of this type of game mechanic -- elements that are perhaps too forgiving to the player -- then it would have to be fear.