Pierce

Pierce is the maximum number of bloons a single projectile can hit before it disappears. A dart with 2 pierce can pop two bloons; a dart with 5 pierce can pop five. It is one of the two most important attack stats in BTD6, next to damage, and mixing them up is one of the most common reasons a defense fails.

In-game descriptions often call pierce "popping power", for example "Can pop 1 extra Bloon per shot."

Pierce vs damage

These two stats answer different questions:

• Pierce: how many bloons can one projectile hit?
• Damage: how many layers does each hit remove?

A Dart Monkey throws darts with 2 pierce and 1 damage, so each dart can pop one layer off two different bloons. A Sniper Monkey shoots bullets with 1 pierce and 2 damage, so each shot hits only one bloon but removes two layers from it.

That is why a Sniper with Full Metal Jacket (1-0-0, 4 damage) and later Deadly Precision (3-0-0, 20 damage per shot) is great against single strong targets like Ceramics, while it does almost nothing against a wide, dense wave of small bloons. A Tack Shooter fires eight tacks with 1 pierce each, so it can hit up to eight bloons per volley, which is excellent against crowds and poor against a Ceramic with 10 health.

A quick worked example

Imagine a tight group of 20 Pink Bloons (5 layers each, 100 RBE total).

• A tower with 1 pierce and 5 damage fully pops one Pink per attack: 20 attacks.
• A tower with 5 pierce and 1 damage removes one layer from five Pinks per attack: also 20 attacks in total, but the damage is spread out, so the group shrinks slowly.
• A tower with 20 pierce and 1 damage removes a layer from the whole group per attack: just 5 attacks.

Now take a single Ceramic (10 health on its shell). Pierce does nothing extra here, since there is only one target. The tower with 5 damage breaks the shell in two hits, while the 1 damage towers need ten.

When pierce matters most

• Dense rounds where many bloons arrive packed together, such as round 49 with hundreds of Greens or round 63 with 75 Leads and a wall of Ceramics.
• Children of popped bloons. Popping a Ceramic releases Rainbows, which release Zebras, and so on. A low-pierce tower gets swamped by the children.
• Races, where players send many rounds at once and create huge clumps.
• Regrow groups, which can multiply if your towers cannot hit all of them quickly. See Regrow.

When a tower runs out of pierce before reaching the back of a group, players call it pierce-capped. The bloons behind simply walk through.

When damage matters most

• Ceramics, with 10 health on their shell (20 when Fortified).
• MOAB-class bloons, which have hundreds or thousands of health.
• Fortified Leads, which need 4 damage.
• Boss Bloons.

How to increase pierce

Upgrades

Many upgrades add pierce directly. The Dart Monkey's Sharp Shots (1-0-0) adds 1 pierce and Razor Sharp Shots (2-0-0) adds 2 more. Check each tower's upgrade descriptions for "more bloons per shot" or "pops through".

Monkey Knowledge

Some Monkey Knowledge adds pierce, such as Extra Dart Pops, which raises the base Dart Monkey from 2 to 3 pierce.

Buffs from other towers and heroes

• Monkey Village: Primary Training, Primary Mentoring and Primary Expertise (Primary towers only), plus the Call to Arms and Homeland Defense abilities.
• Alchemist: Berserker Brew, Stronger Stimulant and Permanent Brew.
• Mermonkey: Abyss Dweller and its upgrades.
• Super Monkey: sacrifices to the Sun Temple and True Sun God.
• Heroes: Gwendolin's Heat It Up from level 4, Striker Jones from level 8, Ezili's Sacrificial Totem from level 7 and Geraldo's Sharpening Stone (sharp attacks only).

Pierce mechanics worth knowing

• Projectiles expire when pierce runs out. Some, like bombs, trigger an effect (an explosion) when they do.
• Area effects stay but stop hitting. Some area attacks remain on screen after using all their pierce, but cannot hit more bloons.
• Fractional pierce carries over. A projectile with 1.4 pierce alternates between 1 and 2 pierce as the leftover fraction builds up.
• Pierce penalties. Some projectiles use up more than 1 pierce per hit, either on specific bloon types or on everything, which limits how well they scale with pierce buffs.
• Pierce caps. Some projectiles, especially ones that create a second projectile on hit like bombs, have a limit on how much outside pierce they can gain. The explosion may benefit from buffs while the bomb itself does not.

Common mistakes

• Buying damage when you need pierce. If bloons leak in big groups but each one dies in one hit, add pierce or more projectiles.
• Buying pierce when you need damage. If a single Ceramic or MOAB walks through your whole defense, you need damage.
• Stacking buffs on capped attacks. Not every attack gains the full benefit from pierce buffs.

Frequently asked questions

What does pierce mean in BTD6?

Pierce is how many bloons one projectile can hit before it disappears. Damage is how many layers each hit removes.

Is pierce or damage better?

Neither on its own. Pierce wins against dense groups of weak bloons, damage wins against Ceramics, Fortified bloons and blimps. A good defense has both.

How much pierce does a Dart Monkey have?

A base Dart Monkey has 2 pierce and 1 damage, or 3 pierce with the Extra Dart Pops knowledge.

What does pierce-capped mean?

It means the tower's projectiles run out of pierce before reaching all the bloons in a group, so the rest walk past untouched.

Which buffs give pierce in BTD6?

Primary Training and its upgrades, Alchemist brews, Mermonkey's Abyss Dweller line, Sun Temple sacrifices and heroes like Gwendolin, Striker Jones, Ezili and Geraldo.