A while back, I made this guide to explain how I build and play Fiddlesticks and after looking back at it, I find it a little primitive and unexplained. So, for everyone who previously read this guide, there isn't really any new information; it's just a rewrite to explain my thought process and reasoning a little bit more and go a little bit more in depth. For those who are reading this for the first time, I hope you enjoy it. Make sure to leave any comments, questions, or concerns down at the bottom and thumbs up the build once you're done!

Fiddlesticks is an AP/DPS carry. This means that he will be among the top damage dealers in the game and is very capable of racking up several kills and assists.
He also has one of the best collections of disruptive abilities in the game. 3 out of 4 of his skills have some form of CC built in (for those of you who just mentally went through all of his skills, ask yourself this; How many people are going to willingly stand inside a mobile ring of death and destruction (a.k.a Crowstorm)?).
This combination of traits means that Fiddlesticks thrives in teamfights where he can deal tons of AOE damage and completely disrupt the enemy team so that all they can do is stand there and take the brunt of your team's abilities.
But what about outside of the teamfights? Well, once you hit level 6, Fiddlesticks can easily transition into the role of Assassin by running into the neighboring lane and ulting in to wipe out the enemy champions and minion wave. Or, Fiddle is fully capable of sticking around in the lane and continuing his assaults on the enemy carry or turret.

Fiddlesticks is an extremely viable champion at all ELOs. He has one of the best nuke capabilities in the game and is probably the best disrupter there is. However, he is squishy as all get-out and his AP scalings are less than optimal. So, I focus more on getting Magic Penetration. This way, no matter how much magic resistance the enemy has, you will still be able to deal extremely close to true damage, which is devastating when your Crowstorm and Bountiful Harvest will both be able to hit for 500 points a tick. I find this to be the best way to counteract endgame drop-off while maintaining early game performance, all while ensuring that you aren't melted faster than your ult can deal out damage.

Greater Mark of Magic Penetration- I take this mark for getting through as much magic resistance as I can. This is really the only viable mark for Fiddlesticks unless you just feel that you can't go on without Greater Mark of Health in this slot.

Greater Seal of Armor- These are my favorite seals because they give a lot of bonus for their cost and they are useful in game against multiple sources. They not only give a little bit more resistance to AD champs, but they also reduce damage from incoming minions, increasing the amount of health you can get back when you Bountiful Harvest. Other acceptable seals would be Greater Seal of Health, Greater Seal of Scaling Mana Regeneration, or even Greater Seal of Vitality per level.

Greater Glyph of Magic Penetration- I take this to make sure that I can hit the threshold of 30 Magic Penetrationeven from my meta. However, there are multiple other acceptable glyphs for this slot such as Greater Glyph of Cooldown Reduction, Greater Glyph of Magic Resist for a slightly more resilient build, or Greater Glyph of Cooldown Reduction.

Greater Quintessence of Magic Penetration- This gives an enormous boost to your magic penetration. Other quints that could be used are health, or AP, but I advice against AP because like AD runes, they drop off early, especially with Fiddle's scaling. So unless you're jungling and really need the extra oomph early, I wouldn't advise AP for quintessences.

Note* There is a reason why my runes focus specifically on magic penetration; and that reason is early game domination. With 9 marks for magic pen, you get 8.55 penetration. 9 glyphs give you 5.13 magic penetration. And 3 quintessence for magic penetration will give you 5.69 magic penetration. When you add these together, you get a total of 19.37 magic penetration. This on most casters is nice, but not as good as some of the other bonuses you could get. But not for Fiddlesticks. This is because Fiddle still has one more trick up his sleeve, A Harmless Scarecrow. This lowers all enemy magic resistance by another 10, meaning that in total, without getting an item for it, you get 29.37 magic penetration, plus you mastery for 15% and you get 30 penetration. This is the average amount of magic resistance for champions and almost all carries start with this amount. Which means that you're doing true damage at level 1 with your skills without investing in any magic penetration. Which is deadly when you consider the starting damage scaled at level one on Reap.

With the release of the new mastery pages, I have 2 mastery pages setup for different situations.

Use 9-0-21 when you know that you're going to be one of the main damage output sources in teamfights:
This mastery page setup is mainly focused around getting Crowstorm up as much as possible. With these new masteries, you start the game with 10% CDR. Fiendish Codex raises that to 20% CDR and Morello's Evil Tome raises it even more to 30% CDR. Make sure to get Transmutation for a little bit more sustainability in the lane (it's about as much spell vamp as a Doran's Blade gives AD champs). As a personal preference, I select Wealth for the option of getting a Sight Ward if there's a jungler or an extra potion or two. Also get Runic Affinity for increased buff duration.
Note* Runic Affinity works on Baron Nashor.

Use 21-0-9 when you have a pretty balanced team and want to maximize your overall damage output:
When you go this route, get Havoc and Executioner . This really amps up your damage output in teamfights and makes last hitting that much easier. Also make sure to get Mental Force , Sorcery, Arcane Knowledge , Blast , and Archmage . On the Utility side, get Good Hands , Swiftness , and Transmutation . This is based around making Fiddlesticks a powerful teamfight winning nuke.

I use:
Exhaust- This spell has tons of uses; both offensive and defensive. This keeps enemies within range of your spells for a little bit longer and the decrease in damage makes it much easier to 1v1 enemies when you have to. It also lowers Armor and Magic Resistance making both your abilities and those of your lanemate's more effective.
Note* You can activate Exhaust while you use Bountiful Harvest and it won't interrupt it.
Flash- This is probably the greatest escape tool in the game. It is also very useful for repositioning a misplaced Crowstorm. But even more beneficial than that, it gives you the ability to 'Double Jump'. This is when you use the blink from your Crowstorm to cross a partial distance and then Flash the last bit. This is especially useful for hitting ultimates from off the screen; making for a surprise move that the enemy can't see coming. Great for launching into teamfights, getting a double kill while the enemy team is hitting your turret during the laning phase, or getting the jump on the enemy when you are 1v1.

Other spells that work:
Ignite- I've seen several Fiddlesticks do very well with this ability. It gives a little bit more to your DPS and it lets you finish off an escaping enemy. But the most important thing to know about this spell is that it significantly decreases health regeneration. This makes the damage from Bountiful Harvest more devastating as well as pretty much wasting the enemy's Health Potion or healing ability like Meditate.
Ghost-This is viable escape/re-position tool also, it's just not as good as Flash in my opinion.
Smite- Only for jungle Fiddlesticks
Teleport- Map control is always super useful; this is just better for a tank or a support than an AP DPS/carry unless your team is SUPER good about placing wards ALL OVER THE PLACE. Then, you can use Teleport to get to the teamfight very quickly, and then Crowstorm in to practically ensure the teamfight victory for your team.
Clarity- This is a fairly useful skill early in the game. However its effectiveness quickly drops off as you buy items. So if you're having problems controlling your skill spam early, then this is a good skill to use as a crutch.

Fiddlesticks really dominates in the lane and thus, I think he's stronger there. But his ability to quickly and harmlessly clean out an encampment should not be wasted. So, if you are taking the top lane; go and wipe out the Blue Golem every chance that you can. This will significantly reduce your Cooldowns and make it so that you never have to recall for mana.
Meanwhile, if you're bot, Fiddlesticks can easily solo dragon as long as he has the mana to sustain Bountiful Harvest. So, once you feel confident or once you have your Fiendish Codex, check with your partner, then go ahead and take out the Dragon.
Another thing to remember are the lesser encampments; namely the Wraiths for when you are midding, and the 2 Lesser Golems on the side lanes. When in the top lane (whenever you are Blue Team), the Golems are a little past the first turret on the other side, but they're still just out of view of the lane itself. So while this is a bit more of risk, the 60 gold is just sitting there and Fiddlesticks can clean this camp fast and at very little cost.
Doing these little things will put you at a significant gold advantage to other strictly laning enemies as well as give you some extra power to make you a force late game.

Note* Keep an eye on the game clock and remember when you kill each monster. Blue Golem respawns every 5 minutes, Dragon respawns every 6 minutes, Wraiths respawn every 1:40 and the Lesser Golems respawn every 1:40.

Note* These items help to capitalize on the magic penetration obtained and also help to make Fiddesticks a more durable champion and increase his overall utility to the team. This helps turn him from a 'walking R' into a champion capable of dealing consistent damage and making monumental moves for your team. This is why every item that I get either gives more than one bonus that is essential to Fiddlesticks, or gives him both offensive AND defensive power as well as some utility. This gives you tons more bang for your gold while making sure that you get the strength that you need within the given item slots.

and -I start with an Amplifying Tome because it dramatically increases my early game damage while nicely leading into my next item purchase. I prefer the Mana Potion over the Health Potion because as early as level 2, you can use Bountiful Harvest to heal yourself so long as you have mana.
Note* With this setup, you start the game with about 30 magic penetration because of runes, A Harmless Scarecrow, and Arcane Knowledge . This means that at 60 points per tick plus 5 from AP, a full 5 second Bountiful Harvest deals 325 damage at level 1, rank 1 against any carry and most DPS champions.

-This is a great item because it gives a lot of early game AP to increase damage output as well as mana regeneration so you can keep in the lane longer. And finally, if this wasn't enough, it gives CDR, decreasing the time between Crowstorms and thus increasing the discrepancy between your kills and deaths.

-More magic penetration means less mitigation by the enemy and less mitigation means more damage being done. Fiddlesticks has the potential to deal a huge amount of damage; so why not make that damage true?

-I get this early to help with mana generation and to get a head start on charging it up. The earlier you can get this in the game, the better.
Note* This item is not mandatory. If you are not having problems keeping up with your spell output, then skip this item and begin working on the next one.

-This item is great. It gives AP, increasing the damage you do, it gives magic resistance, making you more durable, and it lowers the MR of all the surrounding enemies; meaning that you're not just helping yourself, you making every mage on your team more potent.
Note* At this point in the game, you are lowering MR by 30 points because of Abyssal Mask and A Harmless Scarecrow as well as penetrating 39 points from your runes and Sorcerer's Shoes in addition to another 10% from Arcane Knowledge . This means that any opponent with less than 69 MR is taking true damage against your attacks and those with more are having their MR reduced by a further 10%.

-This is like a bigger, better version of Fiendish Codex, meaning that those excellent benefits that you got during the early game transfer into the late game.
Note* This is a pretty cheap item after you get Fiendish Codex. So if I'm doing exceptionally well in the lane (more than 4 kills and the first teamfight hasn't started yet), I'll purchase Boots and then go ahead and upgrade to this.

-A staple on any mage's build. A huge increase to your AP means that that true damage just got more deadly.

-This is to complete the mana tier of the build and add to your AP.
Note* This item can be moved up or down in the build order as you see fit. If you didn't buy Tear of the Goddess, then it is probably best to skip this item .

-This gives 100 AP (130 if you have Rabadon's Deathcap) in addition to armor. But the most important piece of this item is the active. IT WILL SAVE YOUR LIFE! To remember to use it, I usually put it in the same item slot so I always know where it is; for instance I always put this item in the number 2 slot.
Note This item can be moved or down the order as you see fit, for instance, if you keep getting focused in teamfights, buy this earlier so you can make the damage from Crowstorm last longer

- I've seen this item in multiple builds, however I strongly rally against getting this item for Fiddlesticks. Let me tell you why. This item gives you a lot of early game AP, and spell vamp and would later build into a Will of the Ancients, which give you an additional 10 AP, and spell vamp with an aura. The reason that you get this is so that it increases your durability by healing Fiddlesticks more from his Bountiful Harvest as well as giving him a huge health boost during his Crowstorm. But how good is this really? Looking at the item selection above, you get a lot of damage reduction and health as well as overall utility by giving you several bonuses from one source(i.e. Abyssal Mask, Zhonya's Hourglass, and Rylai's Crystal Scepter). These items give you much better advantages than strictly the 25% spell vamp, meaning that there are better items for durability out there that also help out your team. If this still isn't a good enough arguement, look at the build order. To get Hextech Revolver, you would either buy it as your first, or 2nd (after boots) major investment. This means that you get AP, and spell vamp. Great! But what are you giving up? A lot of gold that could otherwise be put toward getting a Fiendish Codex, which does admittedly gives you less AP, but does give you mana
regeneration and CDR, which are things that Fiddlesticks DESPERATELY needs. It also means that you don't get the added advantage of having a strong carry item like Morello's Evil Tome and it negates your catchup branch of having access to Kage's Lucky Pick and Deathfire Grasp. So, I DO NOT advise getting this item.

- Doran's items give great bonuses for their cost, however they are only really effective during the early game. This makes them great items for carries that need that extra boost until they can get that Phantom Dancer or B. F. Sword. But for Fiddlesticks who instantly becomes stronger without any item contribution at level 6, the early game can afford to sacrifice some strength in order to ensure a strong transition into the mid and late game. This does not mean that it's a bad item, I just personally prefer to keep the 197 gold that I would be losing as well as keep an open branching option.

mejaj's soulstealer- I do not believe in snowball items. Especially this one. It does give an extreme amount of AP and CDR, but it's one of the more expensive early game items and the benefits that you get for it are very situational; you could the entire game without ever getting more than a few stacks. And assuming that you do manage to keep stacks, unless you were super fed, you wouldn't get any of the extra benefits until the late game. By then, you could have gotten the surefire stat bonuses from Morello's Evil Tome or any of the other aforementioned items.

- Because of this build, you penetrate a lot of magic resistance. Now, because of the magic penetration formula, all of those flat penetrations and reductions apply first, meaning that they have significantly less magic resistance by the time that you apply percentile penetration. This means that by the time this item is applied, its effectiveness will be nearly worthless. So, unless every single enemy champion on the opposing team is stacking hordes of magic resistance, I would advice against this item.

- This is basically a Sorcerer's Shoes without the movement speed and a small amount of health. This is only really effective during the early game since it doesn't build into anything. That's not to say it's not an awful item, it's just with the small health bonus it gives and because it doesn't build into anything, it's just not as good an early game item as Fiendish Codex.

-The main reason that I don't get this item is because it doesn't fit well into my personal playstyle. It gives mana, health, and AP, all of which can be received with the purchase of Rylai's Crystal Scepter, Archangel's Staff, or Rabadon's Deathcap immediately. But mostly, I'm just impatient xp

Every game isn't going to be the same; each time you're going to want to change just a little bit to adjust to take advantage of the other team's weaknesses and compliment your team's strengths. So, here's a few builds that I use to help out depending on what I'm doing:

Cooldown Reduction:

The Deathfire Grasp and Ionian Boots of Lucidity combined with a 9-0-21 mastery set allow you to get 40% cdr combined with tons of mana and mana regeneration to keep the spells coming with a little bit of extra power from Rabadon's Deathcap. The Rylai's Crystal Scepter is to keep them from running away.

Tank Killer:

This setup allows you to blast away a huge amount of tank health with Deathfire Grasp while getting lowering magic resistance by 30 because of A Harmless Scarecrow and Abyssal Mask. This combined with Void Staff and Arcane Knowledge further drop the mitigation by almost 50%. The Moonflair Spellblade is to lessen the effects of the inevitable CC that you're going to encounter when battling a tank and the Ionian Boots of Lucidity, Deathfire Grasp, and 9-0-21 mastery setup allow a 40% cooldown reduction for spam Bountiful Harvest.

Defensive:

For those game when you know that nothing's going to go well. Deathfire Grasp might work as a deterrent, especially for those who can't afford to lose the health. Mercury's Treads lessen CC effects while Zhonya's Hourglass, Abyssal Mask, and Rylai's Crystal Scepter give you armor, magic resistance, and health respectively. Spirit Visage will help you stay in the game a little longer with Bountiful Harvest.

Matchsticks:

Hey, I was low ELO once too!!

This is a description of how I use each skill, but before I get to that, I'm going to explain why I leveled up each skill the way I did.
I usually start with Reap because the range on this ability is just so large, that the pester ability combined with all the magic penetration makes for a very powerful ability that you can use to repeatedly hit over and over again.
Next I upgrade Bountiful Harvest. This is to both give me a little bit extra to my DPS as well as to give me a little bit of sustainability in lane.
Next I take Terrify. This works for escapes as well as a biding tool to hold the enemy in one place for your lanemate to get a few free cheap hits.
After that, I take my last point for Reap for a while because after that, the damage drops off a cliff and then prioritize Crowstorm, Bountiful Harvest or Terrify depending on how the game is going, and then maxing Reap toward the end of the game.

A huge debate between every player who has ever played Fiddlesticks is whether to take Reap or Bountiful Harvest as your first spell. Well, I contend that it entirely depends on who you're laning against.
Reap gives you tons of early game damage output from far away while giving a silence for casters. Which means that this spell works most ideally against ranged carries who have very little magic resistance and health in the early game but who can deal extreme damage to you if you get too close or against casters with the capability to drop a great amount of damage if you let them get more than a few abilities off.
Meanwhile, you can elect to Bountiful Harvest to sustain. This works best when you're working a solo lane or when you're fighting against a heavy AD melee champion like Jax or Master Yi. To get close and deal any damage means that they have to face the awful power of your Bountiful Harvest and any damage that they dealt will be nullified.
So, Bountiful Harvest or Reap? Check your enemy lane composition first before deciding.

Note* If you choose to rank Bountiful Harvest first, then the skill order remains relatively the same. Learn Terrify for your second skill, then Reap. Next, pick up an extra point in Reap or Bountiful Harvest situationally. If you chose Reap for level 4 rank up, pick Bountiful Harvest next. If you chose Bountiful Harvest, take another rank in Terrify and then rank up Crowstorm at level 6.

Well, let's run down the options.
If I maxed out Terrify all the way ASAP, then a lot of my damage output goes away, which turns Fiddlesticks from a constant nagging in the opponent's mind to the annoying thing that prolongs the fight for 3 seconds. Why isn't this good? Because CC is the tank's job; you're there to do damage. Terrify doesn't fit that role.
What if I maxed Bountiful Harvest? Well, Bountiful Harvest is a pretty good spell, however it relies on 3 factors. 1) The fight can't move anywhere 2) The enemy can't have any CC and 3) You have to be able to out DPS every single enemy champion. None of the above conditions are feasible. So, while taking points in it is definitely necessary, relying on it for your sole source of damage output is ridiculous and unrealistic.
Patches+ Reap=No real reason to level up past rank 2 or 3. So why max it first? Enough said.
The only exception to this rule? Crowstorm. Upgrade every time it's up. Period.
With the suggested skill up order, you get a strong 1-2 punch from Terrify and Bountiful Harvest, tons of damage from your Crowstorm, a reliable getaway tool, and long range bombardment. This finds a nice balance between Fiddlesticks insane CC ability and his heavy damage output.

This is probably the strongest and best disruption in the game. It's great for giving you a headstart for your tower when you get ganked or for interrupting abilities like Absolute Zero or Death Lotus.
The other thing that this is good for is keeping enemies in range of your abilities longer, the most common and infamous being Terrify into Bountiful Harvest. However, something to remember is that isn't a very viable option until Terrify hits about rank 3. Before then, the mana cost for casting both spells just isn't worth the extra 1 second of Bountiful Harvest that you get.
Another thing that it can be used for is to land a point blank ult. Crowstorm has a channel time of 1.5 seconds; which happens to be how long Terrify keeps them in place at rank 2. And take it from me, there is no better feeling than being chased by somebody like Akali, running into a bush, stopping, then casting Terrify and make her watch you channel your Crowstorm on top of her. Combine this with Exhaust and the hunter quickly becomes the hunted. This is SUPER fun. Trust me.

Note* Terrify does not activate tower aggro on you, so using this while your lanemate gets to hit the other team's tower is an effective way to deal turret damage in the early game when the enemy feels as though they need to step in and try and stop you.

Bountiful Harvest to sustain! This is one of my personal favorite skills in the game. Why? I think it's cool.
But all personality aside, this makes you a huge threat to champions that rely on getting in close to do damage. With a little AP and with all the disruptions that Fiddle has, he's one of the better 1v1 champions in the game because of this skill.
A really cool thing to take notice of is that this skill, starting around rank 4, gets to where the 5 second full drain is actually longer than the total cooldown; leading to 'Chain Drains' where you just sit and spam Bountiful Harvest back to back to back. The whole time dealing damage and making sure that you have a decent of health to keep with it.
Bountiful Harvest also gives you some serious lane sustainability. Draining a minion will restore quite a bit of health during the laning stages of the game. And the longer that you're in the lane, the longer you are within exp range and the more chances you get at last hitting.

This has some serious range and early game damage, however due to recent patches, the end game damage just falls off of some deep precipice and never manages to find its way back up.
However, the utility doesn't really ever go away. Silencing several opponents at once is a very effective feat. Every second their casters can't deal damage and their tanks can't throw down CC is another second that your allies can. This is how you win team fights.
The other cool thing to know is that it does still do a tremendous amount of damage early game, especially when you can get it to bounce between 2 enemies back and forth. And with its insane range, there are few champions who can really do anything about it (gosh dang it Caitlyn).
The last thing to know about this skill is that it no longer targets the enemy with the lowest health, meaning that it is much less effective as a farming tool. It does however do a decent amount of damage against minions; meaning that it can be used to push down lanes or tossed into the wolf or wraith encampments to get some real easy gold.

This is what makes Fiddlesticks the true Harbinger of Doom. This is the best ultimate in the entire game in my opinion because it's one of the few still around that are truly game changing. One well placed Fiddle ult can completely turn a game around in a matter of seconds.
Every time this is off cooldown, your team just won the next teamfight. Stay near the back and let the tank engage. Then let the carries get in and wait half a second to make sure that nobody is backing out. Then, start the channel out of range from any hard CC that will cancel, but still in enough reach to blink in. If you don't feel comfortable, use the 'Double Jump' method. This is explained up in the Summoner Spells section.
The next thing to talk about is where to be when you use this skill. Bushes are your friend, so use them and don't be afraid to double jump to get where you're going if you absolutely have to. A kill is a fair trade for a Flash. This method is best used during the late laning phase because you are easily within reach of everything within the area that you're fighting and you are better set up for a double kill.
Terrify into Crowstorm is a devastating combo that is often overlooked. For more details on this, go back up and read through the Terrify section.
Finally, I want to talk about when to use Crowstorm. Use it whenever you're sure that the teamfight is engaged. There's nothing more depressing than starting your channel and then watching everyone run away. Use it when you're sure that you can get AT LEAST ONE KILL. This is an extremely powerful skill so don't waste it. Use it only when you're sure that you can get a fair trade for the cooldown, mana, and time spent setting it up.

Fiddlesticks excels as a massive AOE nuke that wins teamfights and is one of the best disablers in the game. During a teamfight, you can instantly kill a champion of your choice by using Crowstorm, Reap, Terrify, and Bountiful Harvest on the same target. But, LoL is a team game, so unless there's just one carry that has to go, use you abilities to benefit the entire team.
Use Crowstorm, and then Terrify the Carry or champion who is dealing the most damage. This will severely reduce the amount of damage your team is taking. Next, launch a Reap at the tank or character who is giving the most CC. This will silence them and stop the other team from stunning/silencing your team. From there, turn around and start to Bountiful Harvest the Champ who has the biggest damage output(this is usually the Carry that you just hit with Terrify). Now, you have wiped out their damage, and blocked out their CC. Without these 2 factors, their team has no choice but to fall back. Now, if they have 2 champs with large DPS, hit the second champ with Exhaust. This will slow and further reduce their damage output as well as making them more prone to die from your Crowstorm or another teammate's attacks.
VERY IMPORTANT: Unless you are fighting 1v1 or are getting killed, DO NOT Exhaust and Terrify the same target. Reap will hit at the bare minimum 2 champions and silence. Terrify affects another, and your Exhaust should take out another. 1v5 hold pretty good odds in your favor as opposed to wasting a perfectly good ability on a target that is no longer a viable player in the fight.

Overall, Fiddlesticks is most commonly considered a strong competitor in low ELO but quickly loses his effectiveness in higher level games where experienced players know how to counter him. I beg to differ. A variety of CC and a game changing ultimate makes Fiddlesticks viable in all ELOs. There is no nerf or defense against a well played Fiddle.
So, I hope you enjoyed my guide. Please leave any questions or comments below and remember to vote.
But please don't downvote because you don't agree with one piece of my build and if you do, please leave a comment below to explain why.
Mobafire isn't a competition about 'whose guide is better'. It's a database that allows people who are new to the champion to get an idea as to how to play and it's a way for people who have played for a while to exchange strategies and builds in an effort to learn from each other. Downvoting without commenting deprives me and other people that chance to learn. So once again, please comment.
Alright, as I hop off of my soapbox, I just want to say that I hope you enjoyed the guide.
And remember;
THERE IS NOTHING TO FEAR...UNLESS FIDDLE IS NEAR.