Runes

Main Rune - Precision
Conqueror is a perfect fit for samira, her combos are very important so that you can keep using her ultimate in teamfights.

Presence of Mind -Samira is actually kind of mana intensive, so harassing the enemy is necessary to keep your mana up with this rune, and so that you can keep using your ultimate in fights, and survive using abilities.

Bloodline is a nice amount of omnivamp to keep you healthy, extra auto attacks won't do much damage, not as much as your abilities anyway, and going tenacity doesn't make much sense since any hard cc counters samira's ultimate.

Last Stand is perfect, because by the time your use your ultimate ability, you are almost guaranteed to be <50% HP, and that extra damage will help your ultimate ability a lot.
Coup de Grace is acceptable but not really as great because youll get more overall damage out since Last stand depends on your HP and this rune depends on your opponent's HP.

Secondary Rune - Domination
Taste of blood synergizes well with Presence of Mind, to keep harassing, also it scales with your AD (20%), and level. Sudden Impact gives roughly 5-10% extra damage early game, would not recommend over Taste of Blood.
Sudden Impact is a decent rune, it improves your damage by up to roughly 8% in early game, but loses its significance later and cant help you sustain in lane.

Ravenous Hunter is some nice omnivamp to keep your healthy, nothing else really matters, because your passive gives you movement speed, and the only items you need haste on are immortal shieldbow and mercurial scimitar, which both have long cooldowns, and ultimate ability haste doesnt matter because your ultimate has an 8 second cooldown

Itemization

Starter Items
Doran's Blade is a very standard pick on bot lane, if the enemy laners have lots of poke in lane (Ashe, Xerath etc.), then Doran's Shield is definitely a better pick helping you sustain in lane, however Doran's Blade is quite good since taking fights constantly past level 3 is beneficial to you in these matchups, and also keeps them off the wave and denies them CS.

First Back
Long sword builds into vampiric scepter which is really good, because your ultimate and Q both apply on-Hit effects and lifesteal, and it builds into Immortal Shieldbow, the passive shield is a huge lifesaver and lets you take riskier plays in lane and dives under turret for extended periods. If you have some extra gold in lane that you want to grab for a cloth armor or magic resist cloak and long sword in place of vampiric scepter, go ahead, its a smart idea in lanes with champions like xerath who do lots of poke but little damage early game.

Core Items
Immortal Shieldbow is really good. The shield is extremely effective against assassins, the lifesteal it gives is very good for sustaining in lane, since you heal about 40 HP per auto attack near this phase. The Plated Steelcaps can be switched out for Mercurial Treads if they have more CC than you can handle or do more magic damage than physical damage. You can go Berserker's Greave's if you are ahead in lane and dont need to worry about their damage output. Other boots simply dont matter except maybe Boots of Swiftness which reduces slowing effects on you. If you are behind, it is viable to not build/skip boots. The Collector is a great item, it executes if they are below 5% HP, gives you +25 gold on takedown, and gives you 12 Lethality, and 20% crit chance. The extra gold can help you catch up in lane and the execute can help you win/take fights you couldnt earlier. This item lets you build Infinity Edge directly as the 3rd item, however in the state anti-heal is currently in, in Season 11, Bloodthirster is also viable in place of Infinity Edge if you feel that your damage output is enough for now.

Situational Items
Lord Dominik's Regards is a replacement for The Collector if their laners or team is tanky and you do not have enough damage output to kill anyone. As stated earlier Bloodthirster is viable in place of Infinity Edge if you feel that your damage output is enough for now. Wit's end is a very good item against a team which has AP burst champions like Everlynn, Xerath, Lux, or Zoe etc. The bonus attack speed and magic on-hit damage is very nice addition as well. Death's Dance value goes unsaid, because it's so good. It stores 35% of all physical damage dealt POST-MITIGATION (meaning after its been reduced by your resistances), and deals 1/3rd of it True Damage over Time per second, and if you kill the person who dealt this damage, it heals you for 15% of your Maximum HP and cleanses the remaining damage. Mercurial Scimitar is another Magic Resist Item, however it is an active item, meaning you have to press the assigned button to activate it. It's active ability cleanses you of all CC except Airborne, and gives you an additional 50% move speed decaying over 1 second, as well as ghosting. Guardian angel is a revive. It restores 50% of your HP and 30% of your mana, however it does not immediately take effect, and if you die in the wrong place, you may immediately get killed after resurrecting.

The reason I have not included anti-heal items is because it is NOT your job to counter the enemy team. It is your job to deal as much damage as possible to the enemy team without dying.

Abilities

Daredevil Impulse - Passive
For every separate auto attack and ability used, Samira gains one point of Style, starting from E. If you click on an immobilised enemy samira dashes to her auto attack range and keeps them immobilised for 0.5 more seconds, you can follow this up with your E or Q.

Flair - Q
Samira Q has 2 forms one is a bullet, and other is a slash, the bullet is roughly your auto attack range, and the slash is based on whether there is an enemy in front of you. The Q scales with its level so gets stronger in mid game, however falls off a little bit in late game. You can press Q while dashing with E to deal bonus damage to all the enemies you passed through with E.

Blade Whirl - W
Her W blocks in a radius around Samira for 0.75 seconds blocking all hostile non-turret projectiles. Beware, Lux ultimate is NOT a projectile, Senna ultimate however, IS. Yone q wind slice thing, and yasuo tornado are also blocked, and so are ranged autoattacks, targeted/non-targeted abilties that are ranged. Senna auto attacks are not blocked, however the mist soul she pulls out is destroyed. You can use Inferno Trigger while in W, but not in While in Inferno Trigger. You can use her E during the W. One REALLY important thing to note is that using the W by itself counts as 1 stack towards your passive, but using E in between makes the whole thing count as 3 stacks.

Wild Rush - E
Wild Rush (E), a dash, can go through walls. It also increases your attack speed. Nerfed so that it no longer works on allies, and only enemies, it is a TARGETED ability, so you cant use it randomly, it also has a fixed distance, so if you E to an enemy close to you, you will dash a fixed distance past them, you can escape Jarvan R using this, as well as Yorick W, you can also go through walls, like the one behind gromp, for a surprise attack. It deals damage to every enemy it passes through, and if you press Q then it deals additional damage in the same line.

Inferno Trigger - R
Her Ultimate Inferno Trigger (R), deals damage in an area of effect around Samira, roughly 1.5x her auto attack range, You cannot cast your W during this time, but you can use her E. You can cast this during the W though, however doing so will make your W end early. You cannot use your Q either, and you are slowed by about 30%. Using this also consumes all your Style

https://www.youtube.com/watch?v=_R-Rh9YRbdI&ab_channel=Eldimarix <<< check out this awesome video by Eldimarix on how to get an S style (It's way easier than it looks!)

Thanks for reading this guide, it would really mean a lot if you could upvote this guide if it helped!