This is not a professional build, it's a recipe for the most instant damage - instant, as in: if they don't have enough defensive stats there's no chance for flash/heal. Using parts of this build might increase your chances to one-shot someone IF you get a crit. Forcing enemy carry to build defensive can lead to victory.

I'm a simple player, struggling with some of the mechanics of the game, but I follow the professional scene and analyze many aspects of the game. Particularily when it comes to damage potential. This is my first attempt and everything about this build, from items to runes, is centered around Q-the-barrel combo damage. Many of the suggested choices sacrifice defenses, true damage from the passive and utility (cooldown reduction, lifesteal). Thing is, though, Gangplank can win with just one or two barrels.

This guide is intended for players who already have the basic understanding of how Gangplank works, some knowledge of the LoL glossary and, more importantly, how to play the game. In the remaining sections I just highlight how you can try to do more damage with your barrels.

Experienced players might want to skip all the way to The Combo and Damage Table for a compact explanation, because first I point out some details that might be obvious. However, I think many players overlook them.

Noone uses the runes I put up there, because they need defenses and flat AD. If you farm safely and just kill people with barrels, you can try to use some of these. They're here (like the rest of the build) just to illustrate how the barrel damage can be optimally amplified. NOTE: only the barrel damage, your basic attacks and damage from the passive can be lower than with other setups. If you rely on the passive to win, you almost certainly want flat/scaling AD.

These are the optimal runes, followed by more conventional substitutes. For more informations see: Damage Breakdown.

Greater Mark of Armor Penetration gives the best damage
Greater Mark of Critical Damage better damage than AD, but not as good as penetration
Greater Mark of Scaling Attack Damage gives good damage
Greater Mark of Attack Damage gives decent damage and makes early game easier

Greater Seal of Critical Damage gives the best damage, but only if you crit
Greater Seal of Scaling Attack Damage gives good damage
Greater Seal of Scaling Health is what everyone is using most of the time, for safety

Greater Glyph of Critical Damage gives the best damage, but only if you crit
Greater Glyph of Scaling Attack Damage gives good damage
Greater Glyph of Scaling Magic Resist is what everyone is using most of the time, for good reasons

Greater Quintessence of Armor Penetration gives the best damage
Greater Quintessence of Critical Damage gives good damage, but only if you crit
Greater Quintessence of Scaling Attack Damage gives good damage
Greater Quintessence of Attack Damage is what everyone is using most of the time, for better early damage

Gangplanks of today (5.17) all agree, 21/9/0 is the way to go

Gangplank's Offense tree, in order of importance:

• the damage column, from Brute Force to Havoc (11 points) - must have for Gangplank
• Double-Edged Sword (1 point) - optional damage amplification
• Butcher + Feast (2 points) - easier early game
• Executioner + Dangerous Game (4 points) - useful, also: best spent point at this level of the tree
• Sorcery (3 points) - useful

Gangplank's Defense tree is the classic 9 and it's really good. If you use Feast you can take Swiftness instead of Recovery and check if lower regen doesn't annoy you in the early levels.

Gangplank has no business taking any Utility masteries.

There's plenty of guides highlighting Trinity Force for burst and Infinity Edge for damage amplification, Titanic Hydra adds another very effective burst on top of that. It also adds a bit on top of difficulty of hitting someone with a barrel, if you want to reach the full burst potential. See: The Combo.

Core:
Infinity Edge is the best physical damage amplification item - just read the description
Trinity Force gives Gangplank the extra burst. If it's not on cooldown, Spellblade passive adds 117-224 physical damage (before defenses are applied) to the barrel explossion, depending on Gangplank's level. This damage DOESN'T crit.
Titanic Hydra passive/active is applied on Q wherever it strikes. However, just like Statikk Shiv, if used with E it's only applied to the first barrel and deals damage around it. Using those items makes chained barrel explosions less effective than with other items. With this build, using the Active: Crescent with Q-on-a-barrel adds 150-314 physical damage (before defenses are applied) in a cone behind the FIRST (and only the first) barrel hit, but that cone of damage doesn't ignore any armor, unlike the barrels. This damage also DOESN'T crit. Buying more health is NOT an effective way to increase your damage.

Penetration:
Last Whisper, even though Gangplank can live without it, is the best penetration item for Gangplank's barrels when the enemy has 100 armor or more (that means one armor item, even Seeker's Armguard), so it's almost always the best way to amplify your barrel damage after the core.
Youmuu's Ghostblade gives better results on low armor targets (like ADCs), but because of how the barrels ignore part of the armor anyway, the difference is very small and you should always buy Last Whisper first. For the most damage you want both of those items (even if you use Armor Penetration runes), because as soon as enemy buys one armor item you still have some armor to penetrate.

Other items:
You can add extra small opportunistic damage with Ravenous Hydra or stack more AD. Btw. don't take smite for Enchantment: Warrior - buying 80 AD gives more damage. Depending on your champion level and enemies you face you can squeeze out, at best, extra 20% damage with 6th item, so it's an acceptable sacrifice if you need(ed) boots. Nevertheless, here's how you can get that extra damage.

Ravenous Hydra adds 85-293 damage depending on AD and if the enemy is standing very close to the barrel. See: Item Interactions.

Sword of the Occult is hard to stack, it's in the game just for fun, it's the most AD you can get.

Manamune takes time to stack, but eventually it gives more than 80 AD. See: Item Interactions.

Infinity Edge Bloodthirster Mercurial Scimitar Essence Reaver all give 80 AD and different utility. The best option is a second Infinity Edge for the extra crit chance.

On-hit effects are only applied to the first barrel and interact with it in various ways. If your on-hit effect wasn't active when the first barrel explodes (e.g. 90 stacks on Statikk Shiv) it will NOT be applied to another barrel in a chain if you manage to get it ready between explosions. Tested on patch 5.17 - I think they work as intended and don't expect them to change. These are the item interactions I find relevant.

Starting with the Sheen items:
Trinity Force passive Spellblade works with Q and increases explosion damage of all the connected barrels.
Iceborn Gauntlet similarily increases explosion of all the barrels, but the slowing field only appears under the first barrel.
Lich Bane works with Q but NOT with the barrels. Barrels seem to be immune to magic damage.

Tiamat items:
Titanic Hydra passive and active work with Q, but don't increase the barrel explosion. They create a cone of damage behind the FIRST barrel only.
Ravenous Hydra passive works with Q, but doesn't increase the barrel explosion. It creates a damage circle around the FIRST barrel only. If you have both items, the cone damage from Titanic Hydra's passive doesn't work because they share unique name. You can still get the Active cone.

Other interesting interactions:
Dead Man's Plate passive works with Q, but not when used on barrels (you keep the stacks). Which is perfect for chasing low health slowed targets after the explosion.
Statikk Shiv works with Q and can deal magic damage around the FIRST barrel only.
Muramana toggled bonus damage works with Q, but doesn't work with barrels because that's AoE damage.
Blade of the Ruined King passive works with Q, but it doesn't work with barrels - or maybe it does, but calculates the damage from the barrel's 1 HP, we'll never know.
Essence Reaver passive works with Q, but not with barrels.
Sterak's Gage might seem to fit the build, because it increases Trinity Force damage and therefore the explosions, but it's not worth it.

The theory is simple:

• place a barrel ( Powder Keg), make sure it's ready to explode
• wait for someone to walk into it's explosion radius (maybe they don't see it? maybe it's hidden in a brush?)
• stand on the other side of the barrel (for the Crescent cone to hit)
• use Titanic Hydra's Active: Crescent
• use Q ( Parrrley) on the barrel

If you're standing in a brush with a barrel in front of you, there's a good chance that special someone coming towards you will be dead before they see you. Late game barrels charge fast enough that you only need your enemy to be distracted for a short while to execute it without a vision advantage.

You can only do this every 20 seconds (Crescent's cooldown is the longest), but how often do you find a defenseless ADC walking into your brush of death? Maybe most of the time you won't use the full potential of the combo, but you can do other stuff in between.

Everyone can read the ability description, but there's a lot of moving parts (not just because someone got blown up), variables and formulae that determine the damage in LoL.

Raw physical damage of The Combo consists of:

1. basic attack critical strike
2. Parrrley bonus damage
3. Powder Keg bonus damage to champions
4. Spellblade passive damage from Trinity Force
5. cone damage from the Titanic Hydra Active: Crescent
6. area damage from the Ravenous Hydra Passive: Cleave
7. damage amplification from masteries

Then damage reduction is applied, with all the damage except for the Hydras ignoring 50% of the enemy armor.

At level 18, with the full damage build I described, Elixir of Wrath and Dragon buff #1, the numbers are (rounding down):

1. 488 AD * 2.62
2. 120 Parrrley
3. 200 Powder Keg
4. 208 Trinity Force
5. 293 Titanic Hydra
6. 195 Ravenous Hydra average damage
7. 1278 * 1.05 + 120 * 1.05 + 200 * 1.05 + 208 * 1.05 + 293 * 1.05 + 195 * 1.05 = 2294

To give an example of damage reduction, let's say we have a melee champion with 200 armor, classic 9 points in Defense and no fancy damage reducting abilities.
Our barrels ignore 50% armor, then Armor Penetration from Last whisper and masteries is applied, and then the flat Armor Penetration. This gives us the effective armor considered in further calculations.
(200 / 2) * 0.59 - 39 = 20
In the case of Hydras, only the penetrations are applied.
200 * 0.59 - 39 = 79
If we look up the formula for damage effectiveness we have
100 / (100 + 20) = 0.83
100 / (100 + 79) = 0.55
which means 83% of the barrel's damage and 55% of the Hydras' goes through.
1341 * 0.83 + 126 * 0.83 + 210 * 0.83 + 218 * 0.83 + 307 * 0.55 + 204 * 0.55 = 1853
As far as I can tell, the flat champion damage reduction from masteries will be applied to the explosion and the Hydras, so the final damage is:
1853 - 8 = 1845
Remember, I used Ravenous Hydra average passive damage and rounded down all the way for clarity, so the damage can be higher.

Now we need some real enemies.

• Azir is a relatively hard to kill mage, now has a popular build with Rylai's Crystal Scepter and Zhonya's Hourglass as defensive items, plus scaling Health runes
• Sivir popular ADC with good base defensive stats, let's assume she built Guardian Angel and Bloodthirster which has the full shield, and unlike Azir took Armor runes and classic 9 Defense masteries, but she doesn't see the barrel and didn't press E

Results are:

• Azir with 2716 HP and 120 armor takes 2282 damage and survives
• Sivir with 2004 HP, 136 armor and 350 shield takes 2235 damage and survives

On a side note, with 120 armor vs Last Whisper barrels only notice 35.4 armor, and we penetrate 39. That's what's called "true damage". Azir will take 100% damage (not more) from the barrel explosion itself.

Needless to say, in both cases they are slowed by 80% Powder Keg and Gangplank, if he doesn't kill them on the next basic attack, has Trial By Fire with 612 damage ready. Assuming they really had 2 defensive items to survive that.

You don't need to kill them with the combo, and you might not be able to, so you can go with less damage. Next section compares different options.

Let's compare the build to it's less crazy versions. Assuming it's all around level 18, with Elixir of Wrath and dragon buff #1, our Gangplank shoots barrels. Because we don't have the luxury of 100% crit chance and our opponents don't always walk into the barrel, I include non-crit and chained barrel damage. For The Combo, variance comes from Ravenous Hydra damage. I rounded down a bit - LoL doesn't do that.

Full damage build (crit chance: 45%)
Greater Mark of Armor Penetration Greater Quintessence of Armor Penetration

Champion

Effective Health

Armor

The Combo

no crit

chained barrel

no crit

2716

120

2205 2349

1376 1520

1895

1066

2354

136

2158 2293

1338 1473

1871

1051

Realistic build (crit chance: 45%)
Greater Mark of Armor Penetration Greater Quintessence of Armor Penetration

Champion

Effective Health

Armor

The Combo

no crit

chained barrel

no crit

2716

120

1900

1211

1668

979

2354

136

1862

1181

1646*

965

Replacing runes with commonly used (crit chance: 45%)

Champion

Effective Health

Armor

The Combo

no crit

chained barrel

no crit

2716

120

1672

1097

1439

863

2354

136

1598

1045

1379

827

Other, sub-optimal, damage build (crit chance: 65%)

Champion

Effective Health

Armor

The Combo

no crit

chained barrel

no crit

2716

120

1584

921

1414

853

2354

136

1520

882

1355

817

* See: Damage Breakdown

You don't want to build for the late-late-game 6-item combo if in many games you only have the time and gold to buy 3 items. For the mid-game example we will have level 15 on both Gangplank and the enemy, dragon buff #1, no elixirs. Azir decided to buy Rylai's Crystal Scepter and Zhonya's Hourglass early, but Sivir only has Bloodthirster.

This build's core (crit chance: 30%)
Greater Mark of Armor Penetration Greater Quintessence of Armor Penetration

Champion

Effective Health

Armor

The Combo

no crit

chained barrel

no crit

2165

108

1141

798

978

636

2039

74

1306

419

1110

720

Same items, common runes (crit chance: 30%)

Champion

Effective Health

Armor

The Combo

no crit

chained barrel

no crit

2165

108

1042

725

885

567

2039

74

1173

818

987

632

Skipping Titanic Hydra (crit chance: 30%)

Champion

Effective Health

Armor

The Combo

no crit

chained barrel

no crit

2165

108

988

650

988

650

2039

74

1066

701

1066

701

You forgot the pen runes and are trying to fix it (crit chance: 45%)

Champion

Effective Health

Armor

The Combo

no crit

chained barrel

no crit

2165

108

974

636

974

636

2039

74

1106

721

1106

721

You think this is better (crit chance: 50%) NOTE: they should have 52 and 42 MR with just runes.

Champion

Effective Health

Armor

The Combo

no crit

chained barrel

no crit

2165

108

963

598

788

528

2039

74

1052

657

878

588

Think again (crit chance: 50%)

Champion

Effective Health

Armor

The Combo

no crit

chained barrel

no crit

2165

108

942

590

942

590

2039

74

1051

657

1051

657

It's hard to pin point exactly how much damage an item gives you, because various statistics interact with each other. For example percentage and flat Penetration efficiency depend on enemy armor AND each other. On the same note the amount damage resulting from adding e.g. 10 AD depends on whether you have Last Whisper, Infinity Edge and so on. Numbers in this section are not a simple increase in damage, they just let you compare how useful each item is. Here's my approximation of how the build's parts contribute to the crit damage of a chained barrel explosion in one of the examples:

Greater Mark of Armor Penetration Greater Quintessence of Armor Penetration vs

Source Gangplank masteries Last Whisper Infinity Edge Youmuu's Ghostblade Trinity Force 9x Greater Mark of Armor Penetration Titanic Hydra 3x Greater Quintessence of Armor Penetration Elixir of Wrath Dragon buff #1 9x Greater Seal of Critical Damage 9x Greater Glyph of Critical Damage TOTAL

Damage 254.17 233.18 228.97 225.85 193.63 173.23 92.39 83.32 64.78 42.76 24.67 16.99 12.06 1646.01

Damage contributed by masteries illustrate how much various statistics interact - they would contribute almost nothing without the items, Gangplank's base damages and Armor Penetration.

I also tried to approximate how much damage would other runes contribute in this build:

Runes 9x Greater Mark of Critical Damage 9x Greater Mark of Scaling Attack Damage 9x Greater Mark of Attack Damage 9x Greater Seal of Scaling Attack Damage 9x Greater Seal of Attack Damage 9x Greater Seal of Scaling Health 9x Greater Glyph of Scaling Attack Damage 9x Greater Glyph of Attack Damage 9x Greater Glyph of Scaling Magic Resist 3x Greater Quintessence of Critical Damage 3x Greater Quintessence of Scaling Attack Damage 3x Greater Quintessence of Attack Damage

Damage 42.21 32.21 16.01 16.41 5.79 0 10.04 4.46 0 28.16 21.07 11.28

Once again, those are not exact damage numbers - just an approximation of relative strength. The way to look at this is, for example, Penetration quints will contribute around 6 times more damage to a late game barrel than flat AD quints.

Sometimes getting the gold for items is easier than figuring out how to deal damage. Experiment with items and runes, don't get stuck in a routine. I definitely recommend Armor Penetration runes.
The damage calculations may not be entirely correct. I'm looking forward to you pointing out my mistakes. Also, higher numbers can be reached if the enemy doesn't respect your damage or falls behind.

Armor Penetration For Teh Win.
Enjoy Gangplank.