Primary Expertise

Primary Expertise upgrades the Primary buff to +3 pierce (instead of +1), free tier 1 and tier 2 upgrades, and 25% shorter ability cooldowns (instead of 15%). The Village also gets its own attack, the Mega Ballista: a bolt with infinite range and 100 pierce that deals 10 Normal damage, +270 against Ceramics and +270 against MOAB-class Bloons, every 2.5 seconds. It sees Camo and ricochets to another target within 90 units after each hit.

When to buy it

Primary Expertise is a support for builds that lean hard on Primary towers. Its main uses:

• Pushing tier 5 ability uptime past full when combined with an Energizer, for example on 2-5-0 Glue Storm or 0-5-2 Super Maelstrom.
• Shortening Glue Storm cooldowns in Boss Events and Freeplay.
• Free tier 2 upgrades on many Primary towers placed in range, which adds up in Primary-heavy setups.

The Mega Ballista is a bonus that helps against Ceramics and blimps, but it does not carry the defense alone.

Crosspath 5-2-0 to keep Camo detection for every tower in range.

How it compares

• Homeland Defense costs more, but its ability buffs every tower on the map, whatever its class.
• Monkeyopolis is an income tower, and has no place in CHIMPS.
• Primary Expertise is the right pick only when your damage really comes from Primary towers with abilities.

Is it worth it?

Usually not in a normal game, where Primary Mentoring or Primary Training gives most of the value for far less money. It is worth it in Boss Events, Freeplay and Primary Only challenges built around ability towers.

Frequently asked questions

What does the Mega Ballista do?

It fires an infinite-range bolt every 2.5 seconds with 100 pierce, 10 damage and +270 damage to Ceramics and MOAB-class Bloons, ricocheting between targets.

How much does Primary Expertise cost?

$25,000 on Medium. The page shows the cost on every difficulty.

Is Primary Expertise good in CHIMPS?

Only for ability-heavy Primary builds. In most CHIMPS games, a 2-3-0 or 2-0-2 Village is better value.