This is a guide about Lina, one of the most fun heroes to play (in my opinion ). A simple hero, but with a quite dynamic and aggressive playstyle. Furthermore she is a decent pick no matter the skill level, be it pubs/inhouse/scrims.
I will keep it short, though I'll try to include everything of importance.

Judging from her stats we can see that Lina has

• low hp and armor


• slightly below average movement speed


• slightly above average attack range and decent spell range


• great int gain


• somewhat low base dmg


• a bad attack animation

That means she dies fast when focussed and relies on good positioning and abusing of her ranged disable to stay alive. The int gain is very high, but you'll still have to invest gold into mana items, because she has 2 spammable skills and a very high mana cost ultimate. You will run out of mana many times. Another thing she needs is mobility to get in and out of battles asap.

That means your items will have to provide survivability (primary hp combined with situational counters such as Cloak -> Hood or Ghost Scepter), mana and mobility.

Lina's main role in a game is that of a ganker. She has a very aggressive skillset which works well with other heroes. She is often used as a supportive hero, but shouldn't be the main support hero in a team imo. As I said she should try to fix her shortcomings with items, even though she can function without items as well if needed.
But contrary to popular misbelief Lina is not a cast-and-die type of hero. Her 2 main skills have a very low cd, and one of these skills is an aoe stun, which means she can contribute a lot if she can stay alive in a fight. Her third skill also scales into lategame, allowing her to deal an extra amount of physical dmg along with the magical dmg of her spells. Thus she can also be played as a semicarry, also considering her ability to farm and kill heroes.

As for laning, Lina is a great trilane hero combined with anything that can reliably disable enemies from a long distance. She can harass a lot thanks to her high attack range and nuke, also the burst dmg is deadly in a trilane.
Another option is to put her in a duallane, which was the most common way to play her before the trilane-era.
Solo Lina is compelling because she makes great use of the experience, but it is hard to compete with common solo-heroes because of the bad attack animation. She can spam the nuke to lasthit and harass at the same time from a safe distance, but the common solo heroes would have an easy time outlaning her.

Lina's generic aoe nuke with a nice range, low cd, average dmg and manacost

• note: this skill has a casting range of 600, but can hit units up to 1100 units away; that means that often it's better to click on the ground and not on your target


• long range DS can be tricky to land because the final aoe is quite small

Lina's aoe stun with very low cd, decent range and aoe, average stun duration and manacost

• 600 casting range, 225 aoe; means you can hit units up to 712.5 range away


• 0.5s delay; note that you can interrupt it by pressing s if you think you will miss your target(s)


• 7s cd is amazing on a ranged aoe stun, which is one of Lina's biggest advantages


• destroys trees
  

Lina's utility spell

• great to reposition, escape, chase, autoattack


• improves her dmg output in the mid-late game

Lina's "click -> you're dead" ult

• deals a lot of dmg


• kills stuff

Chances are you have to either buy a Courier or Wards for your team. You need cheap stats and reg. If you don't have to buy Chick/Wards you can replace it with Stick/Circlet/Gauntlet/Mantle.

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x2-3
x1-2

Get Boots asap, those are very important to get in range for stun and to escape. Buy some cheap items to boost your stats, such as Wand (core, too good to pass up), Bracer, Null, Urn. Upgrade your boots. Bottle can be a good option if you plan to roam a lot, but most of the times your solo mid hero will have a bottle, so i tend to skip it even though Lina makes good use of runes.
Smoke of Deceit is cheap and very powerful, especially if your opponents use wards, so you might want to buy some of these to improve your early game ganking, and maybe buy a fresh set of Wards if needed.

Treads vs Phase vs Arcane:


Your early game items could look something like this:

I would advise to get at least one of the items from this category.

Force Staff vs Dagger

Point Booster - cost effective boost to hp and mp, can be upgraded later if needed

Janggo - a great extension if you have a bracer, a nice allround team-item

Euls - mana, manareg, ms and a semidisable which allows you and your team to catch up, as well as land an easy LSA; it can also be used to dodge a lot of crap thrown at you by using on yourself; note that it removes debuffs, most notably silences which is very useful against some lineups

There are other potential choices, which are either situational (such as Ghost Scepter or Cloak -> Hood -> Pipe) or worse than the already mentioned items imo. Nevertheless you should always think outside the box, there is no set build and unusual item X could be your best choice in a given situation.

Your mid game items could look something like this:

Hex - Expensive and hard to build, but worth it and doesn't need much explanation; Lina has a good farming and hero killing ability, so it is not unusual to have enough gold for this item later in the game

Aghanim's - if you bought a Point Booster this is a reasonable upgrade; cheap parts, stronger ult, adds hp and mana

Shiva's Guard - Armor which you lack, aoe slow+nuke is useful as well

Now you have an even bigger variety of items you could go for. I can see a lot of the high tier items being viable if the situation calls for them, so please use your own brain here. Think about what exactly you need the most to win the game, and get that item. This can be items like Necronomicon 3, Ethereal Blade, MKB, Orchid etc. but I don't want to go into too much detail, especially because most games end before you have to consider these items.

Your late game items could look something like this:

Trilane
Harass and deny as much as you can. Try to abuse your range which is slightly higher than most other support heroes, try to not get harassed back too much since you have low armor and low hp. Use your stun to chaindisable enemies and to save your allies or yourself. Be as aggressive as you can unless your trilane is weaker than the other one (for example if you are up against Visage). Take a few lasthits to buy core items like Boots. Lina is very versatile and fits in almost any trilane. You will usually end up with a long range disabler like ES or CM and a carry/semicarry/ganker depending on your strategy. Positioning is key here! You have to stay back so they can't initiate on you, while at the same time not too far back so you can engage in time.

Duallane
This is the oldschool way of playing Lina, usually paired up with a disabler like Sven, SK, ES, CM etc. Lina is a great duallane hero and can be devastating against solos/other dual lanes with a strong laning partner, but will have a very hard time against trilanes. Basically, you play this lane very aggressively. You can go on lvl 1 to harass or even kill an enemy, then go again at lvl 2 or 3 which is often enough burst damage to make a kill. The higher level you are, the stronger are your nukes. Harass as much as possible, and kill whenever you can.

Solo mid
Landing stun can be tricky here, especially if you are up against a high range hero. If you lane vs a melee you can try to stun him when he runs up to the creeps to get a lasthit. Again, you usually want to play as aggressive as possible, since you will get outfarmed in a passive farming battle. Rightclick them as much as you can, use DS to get creeps and harass the enemy at the same time. If you get early boots and your enemy is low hp, you can try to go for a kill with stun. Sadly, this playstyle won't work against some of the top tier solo mid heroes, because they will destroy you if you don't play it safe. Bottle is important and can be the key to win your lane even with your weak animation, so try to get as many runes as you can. Rightclick the enemy hero so his creeps will move closer to you, this way it will be easier to lasthit because your projectile will reach them faster. Try to keep the creeps on your side of the river so you can lasthit and harass from uphill. Your job will be to farm your core items and get as much experience as you can to transition into a strong early-mid game ganker.

Roaming
Lina is a decent roamer. If your trilane is up against a solo lane and your carry doesn't need you to protect him you can decide to roam and help the other lanes. Run around, stun and rightclick people. Smoke can help a lot here, especially if the opponents placed wards. Roaming with another stunner such as VS or ES can be devastating if done right.

Midgame ganks
Not much to say here. You run around with your teammates and kill people. You have a decent disable and a lot of burst damage, especially if your ultimate is up. Often one allied stun is enough to set up a kill for you. You can even solokill low hp heroes (supports) which your full combo. Urn is an amazing item because of the mininuke it gives and free heals after a successful gank. If you managed to get a mobility item such as Force Staff or Dagger your ganks will be a lot more unpredictable and deadly, if you don't have such an item yet you can still use Smoke to great effect. Place offensive wards and put as much pressure as you can on the enemy heroes. Heroes that can initiate a gank for you are of great help, for example a Lion with Dagger or a Storm Spirit. Don't hesitate to use your ultimate to finish off a target asap so he can't retaliate, but don't waste it, always try to make a kill with it (note: make a kill is not the same as steal a kill), it has a pretty long cd time on lvl 1. Push towers after ganks.

Counterganks
Always carry a tp scroll with you (this is basic knowledge and true for any hero). Lina is a great counterganker. Her combo can instantkill that guy who just tried to towerdive your ally, and if it's on cd your stun is often enough to save him and get a kill. Try to work on your mapawareness so you can tp in time, keep in mind the stun is delayed. Sometimes it can be crucial to use DS or Laguna Blade to finish off the enemy instantly.

Once again, positioning is key. You don't want to get initiated on under any circumstance, because that usually means you will die very fast. Stay back, but not too far. Wait for the enemy to initiate, then disrupt their initiation with a stun and use Laguna Blade on one of their key heroes OR follow up the initiator on your team. Do not hesitate to use the ultimate, the faster one of their heroes dies the better. Try to focus and kill one of their key heroes asap. Don't waste your ult on an ES who jumped your team and used all of his spells, if you can kill him before he uses ult on the other hand don't hesitate.

Do not rambo in afterwards unless it's obvious that you won't die. Try to stay alive as long as you can! Your skills have a very low cd, you can use them 2-3 times in a teamfight and continue to chase, also your autoattack hurts. After using your skills your passive skill will give you a decent MS and AS boost, that means you can either autoattack if you think you are safe, escape if it's getting dangerous, chase enemies if you are winning the fight and they flee or just get into a better position. Don't forget to use items such as Eul's or Guinsoo's if you have them. If you have the choice between saving a keyhero (the carry) or saving yourself, you should choose the former in most cases, but don't bother if he is dead anyway and escape instead.

Using LSA


Using Laguna Blade


Friends and foes


Drafting Lina


Pubs, lower level games