Projectile

Projectile mechanics

Radius

Projectile radius determines the size of a projectile's hitbox. If a projectile has a radius of 0, it can only collide with Bloons if its center-point overlaps the Bloon.

Some text, particularly upgrade descriptions, refers to the radius of certain projectiles as the "blast radius", especially for explosions. This refers to the same thing as projectile radius, though explosions and splashes typically have very large radii relative to other projectiles.

Speed

Projectile speed is the travel speed of a projectile.

Lifespan

Projectile lifespan is the amount of time a projectile lasts before disappearing on its own. Usually, projectiles have a lifespan of less than a second, limiting the distance they can travel (typically to slightly more than the attacking tower's range), though some projectiles have very long lifespans, such as the projectiles placed on the track by Spike Factories or shot by Spike-o-pults.