Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Threats to Nami with this build
|Lulu||Lulu loves to poke! Stay on your toes and dodge the skillshots. She's going to be much more mobile than you and your marksman. She has to be close range to use her root, so keep her at arms length, and when she comes in for the stun, grant movement speed with your E to whoever she chains while Aqua Prisoning her to keep her from chasing. Apply this to other poking champions.|
|Janna||Her shield will negate a lot of your harass, so wait for it to go down before engaging or poking.|
Next Level Supporting
Hey guys, Lady Amber here. I'm taking this opportunity to tell you about one of my favorite champions, Nami. She's kind of a jack of all trades, master of none type champion. Her kit has a stun that isn't the best stun, a heal that isn't the best heal, a slow that's not the best slow, and a knock-up that isn't the most instant crowd control. However, she has ALL of these things, which no other champion provides. Her ability to both poke and sustain in lane can be quite overwhelming to the enemy, and her massive crowd control in her ult is great for teamfights.
I would also like to recommend using quick cast with indicators for Nami. You want to quick cast so you can land your skills at the appropriate places at the appropriate times, but the indicators help you see where exactly the curve of Aqua Prison will land and will also help you direct Tidal Wave to land it on enemies at maximum length in order to maximize its slow.
Pros and Cons
Nami's biggest pro is her high skill-high reward function, but it's also her biggest con. Her two most game changing abilities are both slow moving skill shots that can be difficult to land - Aqua Prison and Tidal Wave. Nami has a much higher skill cap than other supports with similar kits, like Zyra, Sona, or Annie who can more immediately land their stuns, but if you can master her, you can truly be a great asset to your team.
Another con to Nami is how squishy she is early. She can easily be targeted and popped before she can get her ult off. The build that I prefer helps alleviate this problem so you can survive the initial burst of a team fight in order to continue being disruptive to the enemy while assisting your team. This build also maximizes her kit's abilities by providing full cool down reduction, a good amount of ability power, and enough tankiness to survive.
Flash is a necessity on Nami. It allows you to escape from gap closers, to position for your Tidal Wave, to go through walls to escape, or to catch a fleeing enemy with an Aqua Prison.
As for your secondary spell, Ignite is my preference because it allows you to dominate lane. However, oftentimes your hand will be forced and you'll have to bring Exhaust. Champions you have to bring exhaust against are Vayne, Jinx, Tristana, and Yasuo. These champions have very obvious windows in which an Exhaust would devastate their damage output.
On Nami, you usually start either Aqua Prison (Q) or Ebb and Flow (W). If you're invading or counter invading, Aqua Prison (Q) is going to be a bigger asset. However, once in lane, your W is going to be your main poke and sustain tool. I would recommend maxing Tidal Wave, then Ebb and Flow, Tidecaller's Blessing, and finally Aqua Prison. If you have a long ranged marksman with you, consider maxing Tidecaller's Blessing so that they can do some heavy lifting in lane.
I go 0/7/23 masteries. These masteries provide you with damage reduction from champs, some health regen, and slow reduction, which is a very precious stat. Slow reduction is only found in two places in league: in the defense tree and on Boots of Swiftness. While tenacity reduces the time a slow is applied, slow reduction actually reduces how much the slow effects you.
Grab all the movement speed, gold generation, potion buffs, and cooldown reduction in the Utility tree. I also recommend taking Inspiration, which grants 20 experience every 10 seconds that you're around an ally that has a higher level than you. This is good if you roam a lot, or if you just happen to drop the XP from a lane minion while you were warding.
Take 9 Marks of Ability Power and 3 Quints of Ability Power. This combined with your Spell Thief's Edge will have you starting the game out with 25 AP.
Grab Seals of Armor and Glyphs of Magic Resist. This will help out Nami's early game (She other wise starts the game with a whopping 19.7 armor) until she's able to get some combat stats from her build.
Start the game off with double red and blue pots, your warding trinket, and Spell Theif's Edge. Capitalize on your ability to poke in lane and get as much gold off your Spell Theif's Edge as you can. Upgrade it to Frostfang as soon as you can, as you get most of its value in lane. Your early core is going to be Sightstone, Sweeping Lens, and Ionian Boots. This is going to provide you with much needed cooldown reduction and some extra damage on your poke.
For your core items, you'll pretty much always have Aegis of the Legion. It's such a strong item, even if it's super boring. Warden's mail will provide you with a bit of armor if you get too close in teamfights, and Frost Queen's Claim combined with Ionian Boots are going to give you close to max cooldown reduction.
Your final build is going to be Ruby Sightstone, Frost Queen's Claim, Randuin's Omen, Banner of Command, Banshee's Veil, Ionian Boots, and Oracle's Lens. In that, you've got around 150 ability power, 130 armor and magic resist, 2,400 health, and full cooldown reduction. Use banner to manipulate side lanes to provide objective control.
Some alternatives would be Locket of the Iron Solari versus large AOE comps or Zeke's Herald if you get your marksman fed early. If the enemy is an HP heavy team and your team is struggling to get them down, don't be afraid to grab Liandry's Torement to help whittle their tanks down.
This is just a rough guide to help you with your build path and set you in the right direction. It's a work in progress that I'll be adding to as the meta changes and as I have more time to work on the coding. I think Nami is a really underplayed champ and you should look into practicing her and showing off her full potential.