What is "arbitrary difficulty"?

[PJ]

Title.

[kmyc89]

TL;DR: Practice by yourself
http://store.steampowered.com/app/348320/Wings_of_Vi_Demo/

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( I had to translate "arbitrary" into my languange to understand your question)

+ It doesn't matter what difficult* (and modiffier**) you choosing- you get Steam achievements (even on the easiest mode( I not saying "easy"): Angel Mode)
+ Achievement-rewards (and story) are the same


* http://wings-of-vi.wikia.com/wiki/Difficulty
** http://wings-of-vi.wikia.com/wiki/Modifiers

[Lowenly]

ar·bi·trar·y (ˈärbəˌtrerē/)
adjective
"Based on random choice or personal whim, rather than any reason or system."

"Arbitrary difficulty" is what could be called random-chance difficulty. It's where your success is NOT based on your skill at the game, but other external factors you have no control over, such as when an enemy decides to attack, or if a boss will create a randomly-generated unavoidable bullet pattern with no blind spot. This could also include "frame perfect" puzzles where you have to start on EXACTLY the right pixel and hold the button for EXACTLY the right number of milliseconds, things that human reflexes cannot consistently do, and so each try is just luck.

Wings of Vi attempts very hard to NOT do this. Its challenges are very hard, but they're not random, and they're not so precise that a little practice and planning can't prevail. The gameplay is more like a puzzle: you're presented with a seemingly-impossible obstacle, and you have to figure out what sort of movements and jumps are needed to "solve" the obstacle. Once solved, it's actually not too hard to pass it again, because you know what you need to do, and figuring that out is what takes the most trial-and-error in this game, not redoing the same actions and hoping that random chance will come out in your favor this time. Most boss patterns are a good example of this: rather than layering simple attacks on top of each other for potentially-unbeatable combinations, bosses use very complex attacks one at a time, each one with its own blind spots.

As the game passes its midway point, however, it simply can't avoid some arbitrary difficulty. The line between "Perform these tricky jumps in the right order" and "Perform these jumps at EXACTLY the right time" becomes blurry, since that's how you increase the difficulty of a precision platformer: you require more precision, sometimes more precision than a particular player's body can physically achieve (without practice).

Ultimately it takes a good amount of platforming skill to recognize when a challenge is just mechanically difficult, and when it's arbitrarily difficult. If you can tell the difference, though, it's easy to understand that arbitrary difficulty is just annoying and unfair: you can't blame yourself, and you can't blame the game, you can only blame random chance, which couldn't care less about anyone.

[Fluid-X]

+1 @Lowenly

[Citronvand]

When luck is a bigger factor than skill, it's arbitrary difficult. Basically what Lowenly said.