This guide is meant for people already somewhat familiar with Gangplank but looking for a different play style with him. I have played GP as my main now for awhile, and have tried all the popular builds. While I think there are many great builds already released (some similar to this one) this is the build that I currently use for both ranked and normal games.

Disclaimer: I in no way claim that this build is the best, or in any way better than your particular build. This guide is meant as a variation that I don't often see played. You may not experience the same results for a number of reasons (but you also risk discovering a new favorite build).

Warning: If you solo queue, people will give you a hard time about building Leviathan. Always. If you are unable to shrug off this initial hostility, then this build may not be fun for you.

Edit 4/26/12: I added a picture of some example matches and tweaked the strategy section.
Edit 8/17/12: I added a new section about the leviathan item. I added a mana potion alternative to starting items.

Because there are plenty of general Gangplank guides, I will instead point out the pros and cons of this particular build.

Pros:

+You are tanky and can dive right in to team fights.
+Your mid game will be good and your late game will be great (snowballing ftw).
+An early Leviathan allows you to power up quickly with assists from Cannon Barrage and Raise Morale.


Cons:

-You will not be the killing machine that you were with a glass cannon build.
-Your early game will be weak until you build Atma's Impaler.
-Your team will flame you as soon as you build Leviathan.

There is room for preference here. These are what I use and why.


Greater Mark of Desolation I have tried attack speed (which is a weak point in this item build) but overall find the armor pen much more useful. These marks will make your early game bearable.

Greater Seal of Armor These are pretty standard. Again, primarily for your early game (although useful till the end).

Greater Glyph of Cooldown Reduction There are several good options here. The reason that cooldown reduction wins with this build (in my opinion) is because of more assists with Cannon Barrage. There are plenty of other reasons to take CD reduction on Gangplank of which you are probably aware. If you need mana regen or magic resist please feel free to switch.

Greater Quintessence of Desolation These will give you more stopping power, especially early game. You won't be disappointed.

Greater Quintessence of Armor Good in the right situation. For top solo these are nice to have depending on your opponent.

Greater Quintessence of Gold I may receive grief for including these, but Gangplank is a very gear-dependent champion. While he is also easy to last hit with, these will add to your snowballability (yes, I just made a new word) in exchange for a less dominant early game.

In the end choose what you like! This is what I play with and why, but you may have better results with your own custom setup.

take what you like. Do you prefer health regen to magic resist? Go for it. This is, again, what I use and why.

Any of those listed below are acceptable. These are very preference based so don't feel obligated to use what I do.

Ghost You need either this or flash. I prefer this because the duration is longer and has more uses imo. I can use this to get back to a lane that is being pushed in addition to chasing or escaping. The added benefit of being able to avoid minion collision also helps this spell hold it's own against Flash.

Flash Many prefer this to Ghost. It really comes down to if you prefer traveling a short distance instantly or a long distance very quickly. It is worth noting that you can flash through walls and such, giving this a more situational flavor then ghost. Keep in mind that you can either flash into or out of a fight (not both). With Ghost you can run in, slap a carry in the face, and run out when focused. Just some food for thought (speaking of food, make sure to eat an orange before running out. Focused = scurvy in a bad way).

Teleport This will give you sustainability early game (basically a free base visit) and mobility for the entire game. A very solid option for Gangplank.

Exhaust A good offensive spell. Better then Ignite for Gangplank imo. It can also be used defensively.

Those are the ones I use. Feel free to use whatever you want. It won't hurt my feelings, I promise.

This is a pretty standard sequence. I pick up Remove Scurvy early for the cleanse (in case of ganks for example) and then prioritize:

Cannon Barrage > Parrrley > Raise Morale > Remove Scurvy

You want Raise Moral for team fights over the extra healing imo.

This is where this build takes a different turn from some of the more popular GP builds. Stay with me and you will be rewarded when you try this build.

Boots and Health Potionx3 to start things off. Mobility and sustainability makes this a great starter bundle.

Edit: I have had some success starting with Mana Potionx1 and Health Potionx2. I find that this helps a great deal when solo laning against a difficult opponent. Without being able to safely run in for a last hit, you will be using parrrley much more. The extra mana can also mean more harass if you have the upper hand. Feel free to try both and see which starting build you like more.

Leviathan as soon as you can afford it. This is an important snowball item that will allow you to shine late game.

Ionian Boots of Lucidity will let you cast Cannon Barrage more often, netting you more assists.

Atma's Impaler will finally give you some much needed Attack Damage. This item is key to your snowballability (there it is again) and will really shine as the match progresses. A cheap item for what you get imo.

Warmog's Armor is next as it will help you stay alive to keep your Leviathan stacks as well as increase your Attack Damage through Atma's.

Infinity Edge will be welcomed at this point in the game. You now have some burst to go with your survivability.

Phantom Dancer will finish things off with some much needed attack speed and crit.

At this point you can sell your boots for whatever you want. I recommend either Bloodthirster, a Trinity Force, or another Phantom Dancer. Remember that item builds are situational depending on group makeups and the flow of the game. This is more of a guideline to how I build, not a set order.

Before I continue, I want to address a core item of this build and why it is important and effective. As a snowball item, I understand that the Leviathan is a risky and potentially expensive (gold per stats) item. The reason why I ignore this risk is because of the success rate I have had with keeping a high number of stacks on Gangplank.

Gangplank has two skills that allow him to net frequent and numerous assists. Raise Morale and Cannon Barrage allow you to quickly build stacks of Leviathan early on. In addition to the ease of obtaining stacks, this build is very durable, often resulting in lower death counts then other builds. If/when you reach 20 stacks, the 15% reduced damage makes this one of the most powerful tanking items in the game. While this may not happen every game, you will typically have enough stacks to make it a worthwhile purchase.

In addition to the statistical benefits of this item, particularly when at full stacks, Leviathan also adds a fun element to the gameplay. I often monitor my stacks as a sort of score or minigame. The thrill of dropping a Cannon Barrage just in time to get 2 assists keeps the game fun and exciting.

Maybe you are in the camp that appreciates snowball items, but would rather see Sword of the Occult on gangplank. One reason I chose Leviathan over the sword is that the nature of the leviathan helps the player keep his stacks (ie makes him more durable). The extra health and ultimately damage reduction can make the difference between keeping or losing stacks. Another reason I chose Leviathan is that it is complimented by both Atma's Impaler and Juggernaut .

While you may not consider Leviathan to be a a competitive item, you may be surprised just how well it works with Gangplank's abilities.

Since you have read this far past all the boring stuff, you are probably ready to hear how the playstyle works.

In ranked games I generally solo top. GP excels here. At this point just focus on last hitting and farming up that yummy gold. There are a few counter classes to watch out for, but it is still possible to last hit with practice. You will not do much damage during this stage of the game, so save parrrley for last hitting. If you are laning with a partner then harassing is more viable. In this case you may want to switch one of your health potions for a mana potion to start.

Your mid game will again be played defensively, with a continued focus on farming gold. The biggest difference is to prioritize team fights over farming. Be careful not to overextend either. Once you have built Atma's, you may have some success ganking. I do not generally recommend ganking at this stage in the game, but every situation is different. Once you get Infinity Edge, you will be ready to bring the hurt to team fights. Find a balance between offensive and defensive playstyle. Ideally you want to contribute as much as possible to team fights without dying. Sometimes you will need to commit and die for the good of the team. Be aware of each situation.

By the end game you will be a damage machine like other GP builds. You will also be very hard to kill. Your stacks will vary from game to game, but they should be substantial at this point (10-20). You will have a lot of assists passively through Raise Moral. At this point in the game you can be initiating team fights, laying down some hurt, running out before you get focused down, and don't forget to shoot a parting shot on your way out.

I do want to clarify that a snowball build is not ideal for carrying a mediocre team. You will bloom late in the game, and it may be too late to come back at that point. That being said, it is a fun build for normal games, premades, and I even went 7 out of 10 on my first solo ranked matches with this same build. While I cannot guarantee similar results for you, I am confident that this build will at least prove to be entertaining if not competitive.

Summary: This is a snowball build (if you didn't read the title) and thus requires patience and farming to exceed. Once you get 20 stacks (this will not happen every game) you will be very powerful. I also think this gives the player a fun mini-game to play during the match. You will have a blast netting another stack by dropping Cannon Barrage on a 1v1. You should be ending games with far more assists then kills (see the next section of the guide for examples of this). Please try this build before you comment/vote. Have fun and thanks for reading.

A special thanks to jhoijhoi for his useful guide-making guide.

Here are some examples of my recent games (normal games in this case). The second match from the bottom is an example of a cookie-cutter crit build that I had to use due to the group makeup. As you can see, this resulted in more kills, more deaths, and less assists. Hope this example helps give you an idea of what to expect from this build.