Blast shockwave stuns bloons at impact, pops bloons in a wider area, and increases Burny Stuff damage.
~ BTD6 description
Shell Shock is the third upgrade of Path 1 for the Mortar Monkey in BTD6. It allows the mortar to create secondary explosions that can stun affected bloons for 0.5 seconds that were damaged near the center of the main explosion radius and/or pop up to one layer of bloon depending on how close to the center of original explosion the bloons were. The secondary explosions will pop up to 45 bloons, just like the explosion pierce cap for previous upgrades. In total it has 45 pierce from the main explosion and 45 pierce from the shockwave.
It costs $925 on Easy, $1100 on Medium, $1190 on Hard, and $1320 on Impoppable.
As the cheapest tower that can inflict stuns on bloons, it can be used as cheap stunners of regular bloons. It becomes most beneficial for reducing progress of Ceramic Bloons from any range.
The relatively low price of Shell Shock makes effective but affordable synergy with Heavy Shells, which benefits greatly from being able to deal extra damage versus stunned bloons.
The advantage of Shell Shock compared to Bloon Impact is that Shell Shock Mortars can be targeted around anywhere on the map.
The only major disadvantage of Shell Shock compared to Bloon Impact is that Shell Shock cannot affect Black Bloons without upgrading to The Big One or without gaining special black-popping grants, as well as that Shell Shock only stuns bloons for half the time that Bloon Impact would.
For most occasions, it is best off using the 3-2-0 Shell Shock for the increased attack speed. 3-0-2 Shell Shock deals more damage through the burning effects of Burny Stuff, but it sacrifices the stunning benefits.
The name is a reference to actual shell shock, though that applies to people induced with trauma rather than referring to stunning bloons.
3-0-2 Shell Shock does not apply napalm through its secondary shockwave explosions.
Shell Shock, as well as The Big One and The Biggest One, cannot stun Black or Zebra Bloons regardless of whether it can pop them or not. It can still stun the children if the bloon was popped by the main blast.
The stun can affect bloons that weren't damaged due to the pierce cap, however the stun still has its own pierce cap.
Before Version 21.0 Burny Stuff changes occurred, the old description for Shell Shock was "Each blast creates a shockwave that stuns Bloons at impact point and pops Bloons further out."