When to pick Janna:

Janna is currently an excellent pick in the tank-heavy meta, due to her ability to protect carries and prevent tanks from constantly harassing them. Janna works well in many team comps, as in every game, an ADC will be a vulnerable and squishy target, hence Janna is an excellent pick to protect an ADC and compensate for their weakness. However, if your team lacks any form on engage, then perhaps Janna is not a good pick, as her strength lies in disengaging rather than engaging. Engage Supports (such as Thresh and Leona) are more favourable in this situation. Also, Janna struggles against poke champions (such as Nami and Sona) in the laning phase, due to their poke dealing more damage than Janna's. While it is possible to be defensive enough to minimise damage and prevent deaths in the laning phase, you may want to avoid picking Janna against poke champions.

Laning Phase:

Although Janna is a very safe laner (Eye of the Storm prevents poke and can prevent death, Howling Gale can stop enemy Jungler ganks or enemy Support engages, and the movement speed provided by Zephyr means dodging skill shots is easier than other Supports), but she is not a strong enough laner to consistently win the lane, due to her lack of engage and powerful poke potential. Unless the opportunity presents itself (such as a jungler gank), do not try and force kills or engages with an all-in, as it will most likely end badly; particularly against other Supports with a strong laning phase or all-in potential (such as Leona). If you and your ADC manage to poke the enemy down significantly, then consider engaging with Howling Gale and Zephyr to slow the enemy, and shielding your ADC to maximise damage. Your aim in the laning phase should be:

- use Eye of the Storm to increase auto attack damage whenever you or your ADC is in position to auto attack, or when one of you is being damaged or engaged upon
- use Howling Gale to disrupt enemy engage abilities (such as a Thresh’s Death Sentence) or buy you and your ADC some time to disengage from an enemy engage (from the enemy Support and ADC, or an enemy Jungler gank)
- poke as much as possible with auto attacks without putting yourself in dangerous situations
- don’t die - if you or your ADC don’t die in the laning phase, then consider it a lane victory, as you have overcome Janna’s weakest point in the game

Some Janna players poke with Howling Gale and Zephyr, followed up by some auto attacks. Unless you are setting up for a Jungler gank, an engage to kill a low health enemy, or to set up for your ADC to poke or chain some CC (such as with Jinx’s Flame Chompers) don’t use Howling Gale and Zephyr to poke for damage. Howling Gale is a very expensive spell in the early game, costing 90 mana at Rank 1, and as you will have very little mana and mana regeneration in the early game, you will be OOM very quickly, making you and your ADC vulnerable. Janna’s recent changes also means your are much slower when Zephyr is on cooldown, meaning you are much more vulnerable to poke, skill shots, or a Jungler gank. Moreover, due to the low damage of both spells, it’s unlikely constantly using these spells to poke will deal any significant damage.

Depending on whether your enemy Support has poke or engage potential will alter the way you should play Janna in the laning phase. Against poke-heavy champions (such as Sona, Nami, Lulu and Soraka) you should avoid trading poke with them at all costs. Your poke deals significantly less damage than a lot of these poke champions, and you will lose most trades. Play these lanes very defensively, using Eye of the Storm to prevent damage rather than to increase poke. I would also recommend buying Ancient Coin rather than the standard Spellthief’s Edge against poke champions, as it provides health, sustain and gold without having to poke unfavourably. Against engage-heavy Supports (such as Leona and Thresh), poke as much as you can without putting yourself in dangerous situations, and always be ready to prevent or disrupt an engage using Howling Gale, and using Eye of the Storm to reduce damage if an engagement occurs.

Roaming/Warding:

Janna has surprisingly decent roaming potential to the mid lane, despite her lack of engage. The AD provided by Eye of the Storm, or the slows from Howling Gale and Zephyr can be the crucial difference between a kill and a close escape from the enemy. Moreover, Janna’s Monsoon has some engage potential, as it can be used to push an enemy to your team, if you get in front of them. There is always the opportunity to Flash and Monsoon your enemy, which can lead to an easy kill in the mid-lane, though this is a risky move which doesn’t always work, so be cautious if you try this flashy play. As with many other Supports, deciding if and when to roam to the mid lane will depend on many factors: who is winning the laning phase in mid and bot lane, how many towers have been destroyed on both sides of the map, and whether the enemy Support and ADC are roaming too.

Janna is also an excellent warder due to her high speed and potential for disengage; Janna can move and ward around the map quickly and ward in slightly risky locations (i.e. deep enemy jungle) while still escaping safely due to her strong disengage.

Team Fights:

Your goal in team fights is to peel and protect your vulnerable carries: stick to them like glue! Howling Gale should be used to disrupt enemies or to keep them off carries, Zephyr should be used to slow enemies who are getting closer to your carries, and Eye of the Storm should be used on either your ADC (to maximise damage and protect them) or a team mate being focused or on low health.

Janna’s Monsoon can be the difference between winning or losing a team fight. The important thing to realise is Monsoon’s dual capabilities: the ability to Heal, and the ability to disengage and reset the fight. If the enemy team have a fantastic engage, or catch out a carry, Monsoon should be used to push the enemy team back and reset the fight; hopefully saving the lives of your team. Monsoon can also be used to prevent a devastating AoE ability from the enemy (such as Kennen’s Slicing Maelstrom) or an assassin from instantly killing a carry (such as Zed’s Death Mark) after getting too close. Finally, don’t forget about Monsoon’s healing, which is quite significant in the late game. Using Monsoon in the back line just to Heal up your team is an effective use of Janna's ultimate.

However, it is possible to use Monsoon to disengage from a fight your team is winning to save the enemy; for example, your ADC is getting focused and killed by the tanks, but the rest of your team is killing the enemy carries quicker than the tanks are killing your ADC, you may use Monsoon to save your ADC, but allow the enemy back line to escape. Deciding if (sometimes Monsoon isn't needed in a team fight if there is no suitable place to heal, and your team has a very strong engage, hence you don't want to disengage, winning the team fight quickly) and when to use Monsoon greatly affects your success as Janna. Analyse the team fight and judge whether your team is winning or losing to determine Monsoon's use.

I strongly suggest never using Monsoon to engage a team fight in the mid/late game, as you will be put in a vulnerable position to die very quickly, and your carries will be much more vulnerable in the team fight.

Ability Order:

This is the standard ability scaling order. Eye of the Storm is crucial to reducing incoming damage, and increase damage from your team; Zephyr's passive movement speed increase and active slow decrease makes it easier to dodge skillshots, roam around the map quicker, and escape enemies; Howing Gale should be skilled last, as only the damage, not the knock-up time, is increased with each rank. It is up to personal preference whether to take Howling Gale of Zephyr at level 2: personally, I prefer Howling Gale, as the knock-up can disrupt the common level 2 all in (such as with Thresh's Death Sentence into Flay) or buy time for your ADC to poke if you and your ADC reach level 2 before your enemy.

Items:

Starting:

Spellthief's Edge is a fantastic starting item for Janna, rewarding poking enemies with gold and providing Ability Power; a stat Janna scales with fantastically. Aforementioned, Ancient Coin is better than Spellthief's Edge against a poke-heavy enemy Support, to provide sustain and gold without the need to take unfavourable trades. I'd personally recommend buying a Stealth Ward to start, as the ward can be used to prevent all enemy Jungler ganks in the early game; although it is fine to buy 2 extra Health Potions instead to have more sustain in the early game. 2 Health Potions and the Warding Totem are essential for sustaining through early trading, and some vision control.

First Back and Laning Phase:

Sightstone is a must buy item early on in the game, and if you have enough extra gold, upgrade Ancient Coin/Spellthief's Edge (Ancient Coin is a more valuable upgrade to get, as you get +2 Gold per 10 seconds). Remember to sell your Warding Totem for a Sweeping Lens! You may also wish to buy Chalice of Harmony (or at least some Faerie Charms) to compensate for Janna's high mana costs in the early game. Boots of Mobility are a fantastic choice, enhancing Janna's speed, thus ability to roam, ward and escape enemies; although you may wish to choose Boots of Lucidity, as Janna benefits well from Cooldown Reduction. However, I would suggest Boost of Mobility over Boots of Lucidity, as 40% Cooldown Reduction can be reached from other items.

Mid and Late game items:

Once the laning phase has finished, I would recommend selling Spellthief's Edge/Frostfang to start building towards Talisman of Ascension, as the active is a great tool for engage/disengage, and the gold generated when you're near a dying minion ensures you generate a lot of gold in the mid/late game; unlike Frost Queen's Claim which has an active that is difficult to consistently land, and less gold generation as poking enemies becomes infrequent. Remember to upgrade your Sweeping Lens to an Oracle's Lens as soon as you reach Level 9! Janna benefits from the standard/supportive 'protect and help the team' items': Locket of the Iron Solari, Frozen Heart and Mikael's Crucible.

Locket of the Iron Solari and Frozen Heart reduce the enemy team's damage, thus helping protect your team, and provides 30% Cooldown Reduction between them; a stat Janna scales well with. Also, Mikael's Crucible provides you with more tools to protect and aid your vulnerable carries, offering you a chance to instantly save a teammate if they are caught by a dangerous piece of CC in the mid and late game (such as Thresh's Death Sentence or Morgana's Dark Binding).

Situational:

Mejai's Soulstealer is a high risk, high reward item, but one Janna benefits from very well due to her safe playstyle and ability to escape enemies/disengage. Moreover, Janna benefits very well from Ability Power (particuarly for Eye of the Storm) and can easily generate stacks quickly, due to her ease of acquiring assists merely by shielding a teammate damaging the enemy. However, I would only suggest buying Mejai's Soulstealer if you are having a good game (i.e. low kills, high assists, won lane) and you're in a game in a lot of kills; if the game is slow with few fights, it will be difficult to acquire enough stacks to justify buying the item. Thornmail is a strong defensive item if you are against an enemy team with a lot of AD, while Banshee's Veil is a strong defensive item if you are against an enemy team with a lot of AP, or threatening skill shots (such as Blitzcrank's Rocket Grab).

Finally, you could build Banner of Command instead of Locket of the Iron Solari, as you still get the defensive aura from Aegis of the Legion, and you can catch the enemy off guard with side lane control and massive minion waves destroying towers. It is up to personal preference, however, and if you feel your team needs the shield from Locket of the Iron Solari, build that instead.

Runes and Masteries:

There's a lot of flexibility in optimal runes for Janna, as she benefits from a lot of stats.

-Ability Power scales well with Janna's abilities

-Armour reduces damage, particuarly in the laning phase

-Mana Regeneration compensates for Janna's high mana costs in the early game

-Health inceases Janna's surviability, compensating for her squishy nature

-Magic Penetration, Armour Penetration and Hybrid Penetration all increase Janna's poke in the laning phase significantly

Test these out and see which work for you!

Janna's masteries match the standrad 0/9/21 Support masteries:

While it is possible for some flexibility (for example, changing Phasewalker for Bandit), I wouldn't recommend putting the points into the Offense branch rather than the Defense branch just to get the Ability Power and extra Cooldown Reduction. While these stats do benefit Janna significantly, you can reach 40% Cooldown Reduction with your items, and the Ability Power isn't a high enough value to justify sacrificing the signifcant defense provided in the Defense branch; without the points in the Defense branch, Janna can be killed quickly and poked to death/out of lane in the laning phase.