Directed Spikes is the second upgrade of the third path for the Spike Factory, it allows the Spike Factory to have target priorities. The target priority is initially set to Normal, its normal target priority, but it can be changed to a unique target setting to make best use of this upgrade.
It costs $340 on Easy, $400 on Medium, $430 on Hard, and $480 on Impoppable.
- Normal: Places spikes like a normal Spike Factory.
- Close: Places spikes at the track part nearest to the Spike Factory.
- Far: Places the spikes on the track part the least close to the Spike Factory
- Smart: Attacks bloons in the most "optimal" position possible by dispersing spikes directed at the bloon that the Spike Factory considers "optimizes" its power. By default, it places spikes as close to the applicable entrance(s) as possible. Also allows it to chase down approaching bloons easier. Otherwise, it places the spikes as most close to the entrance as possible if no bloons are detected within its radius.
- This upgrade is useful for specifically placing spikes along specified points, particularly so for targeting onto intersection points.
Directed Spikes is a rather situational but also useful upgrade to pick for the Spike Factory, as it sacrifices either stronger spike piles (Path 1) or faster production (Path 2) for special targeting of spikes. On most situations, random targeting is sufficient for the Spike Factory to produce maximized spike production, in order to stockpile spike piles everywhere within the tower's radius. However, there are few situations where it would be worth sacrificing one of the paths for allowance of specialized but limited custom spike pile placement. Places where there are multiple paths or intersections on the map are generally wise choices to crosspath a Spike Factory with Directed Spikes.
Along with crosspathing to Directed Spikes, there is the opportunity to further upgrade to Long Life Spikes to make even better use of Directed Spikes. When pursuing further towards Path 3, stockpiling because even more vital for optimizing its performance. Learning the ways of stockpiling spikes effectively is especially important for the final upgrade Perma-Spike.
Before considering purchasing Directed Spikes, consider if it's possible to maximize the potential of a Spike Factory without Directed Spikes. It is worth analyzing the map if it is possible to avoid overscattering of the spike piles due to multiple paths. If so, it is better off going for just Path 1 and Path 2, unless going for Perma-Spike. When setting up the Spike Factory with Directed Spikes, provided that prior Spike Factory optimization analysis was done, consider a spot where the Spike Factory should be able to dispense spike piles specifically at. Intersections are generally the best choices for Directed Spikes to go for, as they will overcome the other Spike Factory weaknesses the most.
- This upgrade is the only target-granting upgrade in BTD6 that will not automatically set one of the new target settings.
- The "Smart" target setting is disputed in how "intelligent" the setting is. Some players even say that some of the functions in the "Smart" target setting send spikes at the worst position if the factory is already in a bad position.
- The "Smart" target setting can detect incoming camos, as indicated by the fact that it will still stockpile spikes on the path of anticipating camo bloons, as if the camo bloons were normal bloons. This is in spite of the Spike Factory not yet counting as camo detection range for the Monkey Sub's Advanced Intel upgrade.