User blog comment:PrayforDawn/What is Difficulty?/@comment-3466579-20140113104431

Mobility, as someone already said, is an issue only when it lacks. With a highly mobile champion you can easily dodge skillshots, position and re-position yourself and run around the map. You mentioned Ahri? So how about escaping a gank / engage without her ulti? The same goes for Riven. Even the less capable players can do well with her thanks to her ridiculous mobility.

Micro-managing definitely adds some difficulty to a champion's playstyle. However, keep in mind that micro-managing generally comes with an increase in the strenght of the champion. Orianna and Syndra have great zoning, Draven has insane damage, Twisted Fate has 3 skills in 1 and Zed has some amazing tricks, all of these thanks to some micro-management from their skillsets. We can say Orianna's difficulty is higher because of her Ball's mechanics but the power she gains from it is definitely balanced with the increased difficulty.

Skillshots can both be a difficulty factor or an ease one. First of all, the difficulty coming from a skillshots depend on quite some champion-side factors: spammability (skill cost and cooldown), speed, range, effects (Ezreal's Mystic Shot vs Blitzcrank Rocket Grab), importance in the champion's skillset (missing Quinn's Blinding Assault vs missing Nautilis' Dredge Line), startup or delay (like Thresh's Death Sentence or Swain's Nevermove). Then there are player-side factors like: knowing the correct range and speed of a skillshot in order to hit moving targets, reading your opponents' minds (guessing their choices) or situations (understanding where they are forced to go), knowing when to actually use the skill. This said, i wouldn't say Ezreal's difficult to play because of his Mystic Shot whereas i think Anivia is a difficult champion to play because of her Flash Frost.

Game Knowledge is a difficulty factor on its own and it can't be related to certain champions exclusively. Your Lux example is wrong and it makes me think you've never seen a decent Lux playing. Lux "can just throw skills out all day from the fog of war don't have to think about this." Lux have a ridiculously strong and easy to land skillshot in her Lucent Singularity, but the rest of her skillset is more difficult to use. In order to throw skills out all day from the fog of war you need map awareness and good mana management; moreover, Lux is a rather squishy champion with no escapes so she entirely relies on her Light Binding in order not to get melted by melees.

From my personal experience, i think the 3 most difficult to play champions in the Leagues are Janna, Anivia and Kassadin.

Janna's difficulty is mainly about her Monsoon which can really easily help the enemy team on a even minimal mistake. She also lacks escapes and Howling Gale requires a lot of experience and thinking in order to be used in certain situations, e. g. when you have to land it a medium to high distance.

Anivia has no escapes and her Crystallize can help the opponents in running away from your team mates. Her mana management is really tight and landing Flash Frost (a rather slow skillshot) is almost mandatory.

Kassadin may seem an easy champion to play, when you look up to those good players dominating with him. However, he is melee, Nether Blade only empowers melee attacks and Force Pulse need charging before using it. After lvl 6 Kassadin gets Riftwalk which is a really good gap closer and escape, however you are still quite helpless against ccs if you Rift Walk without care.

Other difficult champions worth of notice are Lee Sin for his intense and highly active playstyle, Kog'Maw for the care you need in positioning yourself having zero escapes and being really squishy, Lissandra for her need for a point blank engage and ulti management, Alistar for the precision requires in using his Q - W skills and tight mana management and lastly Rumble for the care you need to put in trying to keep yourself between 50 and 100 Heat and his ulti cast in tight situations.