This was originally just a build, so only the build portion of this guide is complete. It looks weird now as it is transitioning to being a more professional looking guide/build, so you might see me writing conclusions before introductions, random pictures, and stuff like that, but it should look really good once I'm done. Please don't give me a vote (up or down it doesn't matter), until I'm finished (maybe I'll just copy and paste to re-post this as a new guide once I'm done)! I've been trying to follow this and this, they will serve as my guide to making this build the best build it could be.

Have any tips for what you want to see in the Chapter Sections? Then let me know because that way you would be helping me to help the both (or all) of us. I am also terrible with English so please be patient with me.

I have gone through many online builds in my adventure with Sivir in attempts to try and figure out what works best for her. I tried out the standard builds and found out that they just weren't for me. So I started developing my own weird concept builds (i.e. HADC&C; Hybrid AD Caster and Carry), and I've slowly managed to perfect it (and update it with every big patch), and I came up with this monster of a build, but along side it I offer the more Standard Non-CDR Substitute.

Cooldown reduction so important, and most people don't even understand why, so I decided to dedicate a whole chapter about it. So how good is CDR? How good is 10% CDR? How about 40% CDR (cap)? To most people at face value it would seem as if 40% CDR is 4x better than 10% CDR, but that could not be more far from the truth. A 10% CDR allows for you to cast your abilities 1/9x more frequently, whereas, 40% CDR allows for you to cast spells 2/3x (6/9x) more frequently. 1/9 x 4 = 4/9, not 6/9. Another example is 100% CDR (again cap is at 40%, so this is only theoretical) allows for you to cast an infinite amount of spells, not considering mana of course. So, you have to remember to view CDR as percents (or fractions). This is why I always stress getting to the 40% CDR cap if you are going to bother getting CDR at all. Why CDR on Sivir when she is an AD carry, not caster? Well, most of her damage (and bonus AS) late game comes from her Ricochet ablility which she can cast every 5 seconds, whereas, the amount of time it will take her to finish all 3 AAs will only take just about 1.5 seconds with this build (at around 1.94-2.02 AA per second; including masteries). Now would you rather get something like Berserker's Greaves for an extra bit of AS (maybe boosting you to around 2.15 AA per second w/ Ricochet active) to reduce the time (~1.5 seconds >>> ~1.4 seconds) in takes to do all 3 of the Ricochet's AAs, or would you rather reduce the 5 second cooldown by 15% (4.25 second) with the Ionian Boots of Lucidity along with all your other abilities? Also note that Ricochet also grants you an AA reset which is not affected by AS (only CDR). Now note that that 15% also helps contribute to get you to the more important 40% CDR which means that your Ricochet can cast every 3 seconds, this also pairs well with Trinity Force's passive: Spellblade which can be activated by a spell every 2 seconds. This is a really great combo for overall high DPS not only against champions, but also turrets because the 3 (main/only) things that can affect your DPS against turrets are AA resetes, AS, AD, and a Spellblade passive.

Riot actually intended for CDR to be used on Sivir. Here's the Riot post: Surrender@20

And here again when they said that Essence Reaver (I don't like this item, but it goes to show that Sivir needs mana regen and CDR) was made to be used by Sivir (among a few other hybrid ad caster and carry champions):Planned [4.10] Patch

Again Riot says that Sivir is one of the champions that they suggest should be taking the Essence Reaver: Patch 4.11

Sivir (55%) was also the second best AD carry (ahead of Ezreal at 54%) on U.R.F. Mode (a mode with no mana costs and 80% CDR; shows that Sivir does well with CDR and mana regen), with the top being Draven (56%):
http://www.lolking.net/news/final-urf-mode-charts
Although I think that Draven's winrate was an error because if it were really 56% then he would have come up ahead of Fizz's winrate on this other link:
http://www.lolking.net/news/urf-mode-charts

W.I.P.

I'd like to start by saying that is the main-main build on this guide page, and The Standard Sivir Build is not. The reason why I say this is because The Standard Sivir Build build was created by me using a general understanding of the way to build an ADC/Sivir (pretty standard with no CDR), whereas the Hybrid AD Caster and Carry build was a very unique build that I personally designed to fit Sivir's kit. I'd also like to note that I personally prefer the Hybrid AD Caster and Carry build over The Standard Sivir Build build, and while initially not as powerful it eventually becomes more powerful (compared to The Standard Sivir Build) once you build either the B. F. Sword or The Brutalizer as your first item on Sivir. Even if you had a B. F. Sword on The Standard Sivir Build build it will still not beat out the same gold value damage on the Hybrid AD Caster and Carry build. Also this build has almost no MR, but you do have a lower cooldown on your Spell Shield. MR sucks anyways as I will explain in the Greater Glyph of Cooldown Reduction in the Runes (chapter) section for this build.

This build is for those of you that are too skeptical to use (or even try out) my Hybrid AD Caster and Carry build. The early game is definitely stronger and more durable on this build, but you do end up getting some mana problems and a much lower damage/utility output late game. Late game you do have more MR on this build, so you do get a little more protection from magical damage (and CC), but you end up with a higher cooldown on your Spell Shield than with the HADC&C build. This build (using the Example build) has 28.55 (not counting Warlord ; 29.9775)) more AD, 5% more CSC, and anywhere from 89% to 49% more AS than the HADC&C build, but has 31.52 less flat armor pen, 40% less CDR, a lot less mobility, 250 less health, 200 less mana, less LS (only 1% though), and no Spellblade/Rage passives.

While this is the weakest level 1 Sivir build on this page, but it is extremely powerful from the point that you buy your first The Brutalizer and beyond. In fact, I would say that just after you buy The Brutalizer this becomes the most powerful build on this page. WORK IN PROGRESS

I made this build out of the desire to have CDR (from the HADC&C build) while keeping all the AS and CSC (actually this one has more of both) of the The Standard Sivir Build build. This is a very hyper-offensive and as such has very low defenses, and is mostly a late game hyper-carry (with CDR). Since this build uses so much AS it's more efficient to get the Blade of the Ruined King than Bloodthirster. You can also go with the 21-9-0 masteries on this build over the 21-0-9 one if you need to be more defensive. Come late game this build becomes the 1st/2nd strongest out of all of the 4 builds, 1st if you are up against high health foes.

• Greater Quintessence of Cooldown Reduction: Sivir is one of the few marksmen that benefit greatly from CDR. With CDR Sivir can make more use of her auto attack reset and attack speed granted to her by casting Ricochet (gives your autos a more optimized dps than going with just attack speed; i.e. Berserker's Greaves+ Phantom Dancer+ Greater Quintessence of Attack Speed+ Fury vs. Ionian Boots of Lucidity+ Youmuu's Ghostblade+ Greater Quintessence of Cooldown Reduction+ Sorcery). She also gets more use of her Spell Shield which grants you mana restoration and protection from enemy spells, Boomerang Blade for a little more burst (and getting that last hit on pesky enemies that try to run away), and On The Hunt which grants lots of utility for the whole team and in some cases (i.e. enemies are on the other side of the map) spam roam for you and your allies (also your minions; if you stand in front of your Nexus then you can ult all three minion waves simultaneously).
• Greater Quintessence of Armor: This rune is completely overpowered right now, it's just too good not to take. Also note that Sivir starts off with 30 MR vs. her only having 16.75 armor to start with. So that is why this build has Greater Seal of Scaling Armor and Greater Quintessence of Armor, but no MR runes. Both supports and ad carries preform auto attacks, but (usually) only the support has magic damage dealing spells, so that is why armor is so important. Greater Quintessence of Armor also pair very well with Greater Seal of Health for the early game.
• Greater Mark of Armor Penetration: Flat armor penetration is useless/worthless (almost) unless if you already have lots of it paired along with percent armor penetration, and that is exactly what this build incorporates. With Greater Mark of Armor Penetration, Youmuu's Ghostblade, Last Whisper, and Devastating Strikes giving you a total of 31.52 flat and 38.9% (not 41% because Last Whisper is applied before not with Devastating Strikes ) armor penetration. That is crazy good, Sivir's Boomerang Blades will now hit really hard (especially on squishies) along with her basic attacks. In any case my general rule of thumb for Greater Mark of Armor Penetration, is that when taking Youmuu's Ghostblade on a champion (marksmen or ad caster/bruiser; doesn't matter) then you should also be taking Greater Mark of Armor Penetration.
• Greater Seal of Scaling Armor: I usually don't build a armor item, so I really need this for late game. Basically for late game I need the 27 armor from Greater Seal of Scaling Armor to go with all the Health/LS/Shield (which all effectively are Health) from Trinity Force and Bloodthirster. While for early game you already have the Greater Quintessence of Armor which already makes you pretty tanky. Also Greater Seal of Scaling Armor become even with the Greater Seal of Armor by level 6, and then greatly out scale them afterwards. Greater Seal of Armor are underpowered and really suck right now. Another option for more early game protection to take for your seals would be 9 Greater Seal of Health. With Greater Seal of Health paired up with your Greater Quintessence of Armor you become pretty tanky early game with multiplicative scaling to your defenses.
• Greater Glyph of Cooldown Reduction: You take these basically for the same reason you take the Greater Quintessence of Cooldown Reduction. You need that last 7.5% of cooldown reduction. Also note that you will be taking this opposed to Greater Glyph of Scaling Magic Resist or Greater Glyph of Magic Resist, which frankly in my opinion suck to begin with. The reason why I don't like MR glyphs is because you already start off with 30 MR, so having the flat MR glyphs will do you almost no good against Supports considering that they have pretty low AP to begin with. Then there are the scaling MR glyphs, the reason why I don't like those are pretty simple: you only start off with 30 MR. Basically if I go up against an AP mid lane (or even top lane now, and sometimes jungle), your now 57 MR (30+27) is basically useless because AP champions have access to magic pen items and runes without having to sacrifice any damage items/rune. What I mean by that is that they (usually) get a flat 22.83 (unless if they get Greater Glyph of Magic Penetration and/or Greater Quintessence of Magic Penetration) magic penetration from 9 Greater Mark of Magic Penetration and Sorcerer's Shoes along with 38.9% magic penetration from Devastating Strikes and Void Staff, so your 57 MR now is actually only worth 11.997 MR. Considering that most MR items in the game have considerably lower values than the armor ones and the fact that you can't sacrifice many of your item slots for defensive items (being that you are an ADC, well actually HADC&C; your 2 defensive items in this build are Trinity Force and Bloodthirster), you really shouldn't bother to take one (MR item). Just accept the fact that you will be squishy against AP carries, and pair your self up with a Morgana for her Black Shield or Braum whilst using your own Spell Shield for as much protection as possible. Also with the extra health and shield (and again Spell Shield) from both your Trinity Force and Bloodthirster you should be able withstand any immediate AP burst all by yourself, as well as life steal some health (LS gives you even more effective health on top of your existing defenses).

• Greater Quintessence of Armor: (Same as above)
• Greater Quintessence of Attack Speed: Sivir has a really high base attack speed, so taking this along with Fury greatly increases her dps early game. I would have preferred to take Greater Quintessence of Attack Damage because Boomerang Blade does not scale off of attack speed (and for last hitting), but it is a seriously underpowered rune right now and you won't get as much multiplicative scaling (so it just wouldn't be worth taking).
• Greater Mark of Attack Damage: Helps significantly with earlygame last hitting, and is a good early damage option for ad carries. Whereas, Greater Mark of Armor Penetration wouldn't help with last hitting because minions start off with no armor. Flat armor pen is great to build if you have a lot of it already. I.e. going from 20 to 31.52 flat armor pen is significantly better than going from 0 to 11.52 flat armor pen; Youmuu's Ghostblade + Greater Mark of Armor Penetration is better than just getting Greater Mark of Armor Penetration alone. Also note that because this build does not use CDR the amount of benefit you will be getting out of armor pen will be less, as you will be casting less Boomerang Blades.
• Greater Seal of Health & Greater Seal of Armor: Since the Greater Seal of Armor are really weak (alone) it is best to have a mix of both to get some multiplicative scaling. IMO, just getting Greater Seal of Scaling Armor is the best option right now (but it isn't considered standard). You can also go with 2 Greater Quintessence of Armor, 1 Greater Quintessence of Attack Speed, and 9 Greater Seal of Health for more early game durability.
• Greater Glyph of Magic Resist: Gives you some early protection against the enemy support (and hybrid carries), not much support against the enemy AP Carry lategame though (with all their magic pen). If you want better protection against the enemy AP Carry, then you go Greater Glyph of Scaling Magic Resist.
• Greater Glyph of Mana Regeneration: It helps with Sivir's early game mana problems, and many pros (e.g. Doublelift, WildTurtle, and Rekkles) run 4 of these on their (ADC) rune pages. If you want though you can switch them out for more Greater Glyph of Magic Resist, Greater Glyph of Scaling Magic Resist, or even Greater Glyph of Attack Speed.

Best Supports for Sivir include:

• Morgana - Dark Binding is a long ranged skill shot that roots the target for a relatively long duration (while target is rooted you can make great use of Boomerang Blade), great AP harass from Tormented Shadow (possible KS though), her Black Shield in sequence with your own Spell Shield will protect you from most if not all possible ability damage that your enemies have in store for you. And her ult Soul Shackles is not the best (because of the delay), but it's great at locking down and/or scaring away multiple targets (possible KS though).
  
• Leona - Despite Leona melee ranged basic attacks and low range on her abilities she makes up for it in her ability to move in close, tank damage, and harass with her low cooldown and low mana costing abilities, her ult is amazing and she is best played with an aggressive play style to support Sivir
  
• Braum - His Concussive Blows passive synergizes very well with the auto attack reset (and AS) on your Ricochet.
  
• Nami - Ult is boss for knocking enemies up (so much range), stun, and she heals you.
  
• Sona - Hymn of Valor makes for an insanely strong Boomerang Blade early game, bonus armor and resist, speed boost, heals you, and ult stuns.
  
• Thresh - Hook, knock up, ult slows, lantern for mobility and shield.

[*] Gragas

Good Supports for Sivir include:

• Blitzcrank - Hooks , knock up, silence from ult; watch out for KS from ult's passive.
  
• Karma - Snare, slow, shield, and speed boost.
  
• Lux - Her stun is a skill shot with almost as much range as Sivir's Boomerang Blade, long range harass, shield, and slow.
  
• Annie - She's okay with her passive stun and burst AP damage; Tibbers is good for tanking turrets, but watch out for KS.
  
• Taric - Armor bonus passive (500 range), heal, stun, and ult makes Boomerang Blade very strong. He is, however, a melee champion with short spell range.
  
• Zilean - Speed boost, slow, ult revives, and bonus 8% experience for the team; KS from time bomb.

Cost:
{Optional: (# of potions x 35; assumed quantity: 1) + (# of Vision Wards x 100) (# of Stealth Wards x 75)} + (# of Doran's Blade- sellback cost(s); 264 per blade, assumed quantity: 1) + Youmuu's Ghostblade + Ionian Boots of Lucidity + Last Whisper + Trinity Force + Infinity Edge + Bloodthirster = 17327 gold

Post-Lategame: 17327 gold + Enchantment: Furor + Greater Stealth Totem = 18277 gold

Reasoning Behind the Final Build

This build differs a little from the other Sivir build a little (well a lot actually), but I wouldn't really bother posting it if it were the same build that everyone else was posting.

Flash is the standard spell for pretty much every champion in the game. You will need this spell for both going in for kills, and escaping from death. It can also be used for flashing over walls which is great for both putting and closing distance between you and your foes. Sivir has no form of a gap closer/extender, so she's pretty much required to take Flash.

Heal is great for a bot lane since the spell can be applied to both you and your support both healing you two and granting 30% bonus movement speed for 1 second. This can be used as both a great escape or for out trading/chasing (you come out of the trade with more health) the enemy carry and support. It is a very standard pick for the AD carry (or in some cases the support).

Ignite is a great summoner spell for picking up kills and countering Heal (which is being used a lot in the current meta), and it is paired up very well with Exhaust. If you and your support manage to Exhaust and Ignite the enemy ad carry, then that will increase your chances of picking up a kill. It's your (you and your support) choice really on who should take Exhaust and who should take Ignite. Generally you might want to let the ad carry have Ignite (as to ensure that they, not the support, get the kill), but if your ad carry has low mobility/gap-closers/positioning compared to your support (as is the case with Sivir; being that Ignite only has 600 range compared to Exhaust having 650) then it might be better letting your support take Ignite while you take Exhaust.

Exhaust is a very good summoner spell for either your support to take or you as Sivir. The reason why it can be a good idea to take Exhaust on Sivir (or her support) is because of her unique kit and position. As Sivir your kit offers you tons of movement speed (easily breaking you through both of the soft caps), but absolutely no form of CC whatsoever. Exhaust can be that form of CC that Sivir desperately needs in her kit, and unlike her movement speed this slow will not be put through a soft cap (unless if the target was already slowed by a more powerful slowing effect than your own). Sivir also plays the position of AD carry which makes her a very easy/squishy target for high burst assassins (e.g. Akali), so taking Exhaust will both help you survive their burst and in some cases out trade an assassin. Lastly, if you are playing the HADC&C Build the 10 flat armor reduction from Exhaust pairs well (especially during the early game) with the 31.52 flat penetration from greater mark of armor penetration and Youmuu's Ghostblade making your targets very squishy (and makes squishies even squishier).

Also note that even though Exhaust has 650 range (your auto attack has 500) it could still be dangerous to go in to Exhaust an enemy whereas Heal can be used safely from any distance (except when used to heal an ally you must be within 700 range of each other). The same thing applies for Ignite which only has 600 range. Last thing that I want to mention is that you and your support should either be running a Flash+ Heal and Flash+ Exhaust lane or you should be doing a Flash+ Ignite and Flash+ Exhaust lane. It shouldn't matter too much who has which pair of summoner spells it just matters that either of you (ad carry and support) choose one or the other. (Edit): Actually a double Flash+ Exhaust lane works pretty well, you just have to make sure that you don't exhaust the same target at the same time (within the 2.5 second duration). It's also very good to have multiple Exhausts in a teamfight (again don't exhaust same time/target) because there are generally quite a few high damage dealers on a team.

> > >

On The Hunt really doesn't need an explanation, with it being Sivir's ultimate granting insane movement (for you and your allies) and attack (just for you) speeds you should always take a point in it whenever you can. Next ability in the sequence would be Boomerang Blade. This is your strongest ability early game, so you'll want to max it by level 9. Third, you'll want to take a point in Spell Shield at level 2 and max it by level 13. The reason why you will want to max Spell Shield before Ricochet is because of Sivir's overall high mana costs on top of her building CDR in this build. However with CDR (and maxing Spell Shield second) you will be able (with no mana cost) to cast more Spell Shields which means more mana restored to Sivir, that will help to combat Sivir's early to mid game mana costs (by level 18 she has the second highest mana regen rate out of all the champions and the highest mana pool out of all the AD Carries, as well as getting 200 more mana from Trinity Force in this build combined with three points in Meditation ). Lastly you take a point in Ricochet at level 4 and max it out at level 18, the reason why you do this is because you only need one point (before level 6) in order to be able to gain access to both the auto attack reset and attack speed (from On The Hunt) on Ricochet. Taking extra points in Ricochet will do nothing, but lower it's CD and bounce damage (both of which are not as important as taking points in Spell Shield). However if you are paired with a Braum, then I would advise taking a point in Ricochet at level 1 (and still maxing it at level 18) this is because the auto attack reset granted by Ricochet synergizes very well with Braum's passive Concussive Blows

Counter's and Bans:

• Fizz (only for HADC&C build)
• Miss Fortune
• Vayne
• Draven
• Twitch
• Leona
• Amumu
• Alistar
• If you get countered by range then get an aggressive support like Leona, Braum, or Gragas.