Heimerdinger is a champion that has received sweeping changes over his life span in LoL. Bottom line though, he is underplayed. Yes, its true that he doesn't have 3 turrets anymore, and yes you dont get two turrets at level 3... but none of that matters with the ammo system. It is the defining characteristic that makes Heimer OP. Wana gank? Boom! Two turrets in their face. Getting ganked? Run away... but if they are dumb enough to chase you, you are nuking them the entire time.

Pros:
1. Best farmer in game.
With Heimerdinger, you can go back, buy items, and STILL be farming. No other champion can boast that ability.

2. Good kiting.
With Heimer's rockets, you never have to stop to attack the champions chasing you. Just hit W and keep running.

3. Highly maneuverable.
With the H-28G EVOLUTION TURRET you dont have to be directly in the middle of battle. This allows you to stay further back, affording you extra distance between you and those scary gankers.

4. Good CC!
Between your ultimate and CH-1 CONCUSSION GRENADE you can slow and stun the enemy into oblivion. This is only compounded if you add a Rylas into the mix.

5. Superb damage.
More times than I can count, I have downed baron @ 20 mins with nothing more than Heimerdinger, his turrets, and a REALLY good tank. Heimer is a beast in terms of sustained damage output.

- - - - - - - - - - - - - - - - - - - - - - - - - - - -

Cons:

1. Squishy if caught where he shouldnt be.
Heimer is great at staying back, but for the few short moments you come forward to place a new turret, you are extremely vulnerable. Dont go where you dont belong if you arent sure the area is safe.

2. Goes down quick if focused in team fights.
It is important that your team mates understand that you do a VAST majority of the damage in a team fight. A fully spec'd Heimerdinger can bring roughly 1100 AP to a team fight. With two fresh turrets, a rocket, and a grenade all timed properly, you bring well over 800 DPS to a team fight. If your team mates leave you alone to pursue a kill, you might end up dead with them following you not too long after.

3. Skill shots are tough.
The hardest part about Heimer is mastering his skill shot. You only get a stun from the grenade if you directly hit them with it. Even after a year and a half of playing Heimer, I still only manage about 60% of my hits causing a stun.

To anyone who wants to understand why I chose the masteries I did for my Heimer build, I can only say that I cant see it being done differently. With this setup, you gain MAX benefit from the Archangels Staff's while maximizing your cooldowns.

Teleport and Flash. Why those skills? Simple. Teleport allows you to stay in lane early game, and gank late game. You are covering all your bases assuming it is off cooldown. Teleport can be used for two important reasons. Ganking and protecting your assets. If you see that your team mates are being ganked, teleport in behind the gank and set up shop with your turrets. even if you are in the middle of a minion wave, you are likely to make them turn. Assuming you have team mates that aren't brain dead they should try to fight near your turrets for max benefit. Teleport can also be used to escape from a hairy situation since, unlike blue pilling, teleport isnt interrupted by anything short of a stun. Why Flash? Even though its recieved a nerf, it is still a great gank avoidance. People see the flash and most of the time (early game) will break off the gank and consider it a success. Keep in mind though, Flash is a one and done skill, meaning that once you have used it its down until its off cooldown. Play it safe after you use it.

The skill sequence I put up there is the optimal one. It will allow you to maximize your damage while conserving your mana in early game by limiting your spamability. I say that it limits you, but if you are using your skills properly you will be keeping them push back pretty far. If you are worried about ganks and are good with the skill shots, you can take the grenade early on. A word of caution for those that do... The base level of grenade is good for little else other than stunning. It will EAT your mana alive. Not recommended. Now I do get flak for not maxing Heimer's ult, but I think it is 90% useless. I dont care about saving my turrets from dying most of the time. I dont care because I can put them RIGHT BACK DOWN AGAIN. The cooldown reduction is nice, but you wont notice the benefit until late game anyways. And once again, until late game, you wont be involved in too many team fights were your turrets slowing will be of any help.

TL;DR Stand back and spam everything.

This rune setup does only two things. MPEN and CDR. This setup takes max advantage of both. In doing some math, I found that all the Seals combined would be close enough to the amount of CDR from the Quintessence that it was of benefit to ditch one CDR Quint for additional MPEN. Like I said, max benefit. Now, a lot of people point out that this setup leaves Heimerdinger with very little HP overall. Yes he is squishy, but he is a ranged Nuke. RANGED NUKE. Keep him back and it wont be a problem. If you need more HP, buy it in the game.

Heimerdinger has a unique property associated with his turrets. Once he places one and leaves it alone, if it gains a kill when he is not nearby, not only does he get the kill but in addition he receives the gold. This is the basis behind my farming technique with Heimerdinger. When Heimer is mid, and there is no jungler on your team, this is when he really shines. I know that this is a rare occasion, but it does happen. Best part is, you dont have to change your items to accomplish the same result. First i will go over how to farm with heimer while you are in lane.

Place your turret near the middle of the minion pack. this will provide you cover if you need to protect it, and cause melee champs to collide and go around any minions in an attempt to kill your turret. after that, start auto attacking every minion that you can. when they get low on health, spam rockets to clean up the kills. In addition to farming, if you do it right, you can harass the enemy champs at the same time. Voila, farming in lane.

This is where heimer shines! Once you get to level 5 you need to have the following skills. 3 ranks in your turrets, 1 rank in rockets, and 1 rank in your grenade. after this, save up two turrets and, when you have JUST killed a minion wave in mid, go do blue golem. Start by placing a turret, follow it up quickly with a stun from your grenade, and spam rockets, then finish off the combo with your second turret and auto attack it to death. Remember to hit it with rockets and grenade each time they come off cooldown. Your objective is to take the blue buff with as much health as you can, not save mana. after that, get back in lane. Each time you clear a minion wave, go kill a diferent neutral minion camp. Use a turret, then follow up with a grenade and rocket combo then go back to the lane. If anything is left alive, chances are that your turret will mop it up, if not you can grab it next time. Red buff requires the same planning that blue does, so keep that in mind. DO NOT GO FOR DRAGON SOLO, I just dont recommend it as it requires someone else to tank it most of the time.

Heimerdinger fairs very well with a multi-AA build. Ideally, you would have 4 AA's end game, but your largest situational item is going to be Rylai's. I would only reccomend building a rylais if you are being focused and need more slow to kite enemies into more damage. You have the added bonus of getting higher health and a little bit of mana.

I team fights, you should try to land your grenade as best as you can. Even if you miss, you will land a blind at the minimum, and that helps too. Get your turrets in there because they will start wrecking shop. Spam everything as much as you can.

just make sure you arent getting focused yourself.