Advanced Difficulty

 is one of the track difficulties the player can challenge in the Bloons Tower Defense games.

The tracks are harder and are usually short, have multiple paths, or have changing parts or track gimmicks.

In Bloons TD 6, these maps often start to take advantage of intrusive Line of Sight blockers, requiring the player to plan out as majority of available map coverage is blocked for the sight of most towers. Certain other Advanced Maps take advantage of simplistic but challenging twists into the game, as is the case for Geared's tower-moving mechanics or X Factor's lane structure.

In general, tracks on Advanced Difficulty tend to be easier than Expert tracks but harder than Intermediate tracks.

Bloons TD 6
The Advanced Maps in Bloons TD 6 are:
 * Another Brick
 * Off The Coast
 * Cornfield
 * Underground
 * High Finance
 * Peninsula
 * Pat's Pond
 * Cargo
 * Spillway
 * Geared
 * Mesa
 * X Factor
 * Sunken Columns

Bloons TD 5
The Advanced Difficulty tracks in Bloons Tower Defense 5 are:
 * Mount Magma
 * Switch
 * Lightning Scar
 * Downstream
 * The Eye
 * The Great Divide
 * Scorched Earth
 * Rink Revenge
 * Dune Sea
 * Crypt Keeper
 * Candyland
 * Battle Knot
 * Cash Money (Co-op Mode only)

Bloons TD 5 Deluxe
In Deluxe there are two additional advanced tracks:
 * Floating Islands
 * Tubular

Bloons TD 5 Mobile
There are an additional five advanced tracks exclusive to Mobile/Steam:
 * U-Turn
 * Challenger Deep
 * Phase Portals
 * Siege
 * Long Range

Trivia

 * Starting from Version 23.0, tapping on a locked track in BTD6 will pop a message about unlocking previous maps by difficulty. Incorrectly, Advanced Maps were written as "Hard". Link for bug report.