Manton Effect

The Manton Effect is a common tendency among powers to affect either living targets or inanimate objects, but not both. This seems to be a manifestation of a more general tendency of powers to be limited to facilitate their use by humans; more specifically, powers tend to have "in-built" controls to avoid harming the parahuman using them. This phenomenon was first recognized and codified by William Manton.

All powers come with certain limitations - they might only target certain materials, have a limited range, limited precision, and so on. For most (but not all) powers, their range of effect stops at the outside of a person or animal’s body. Many of the exceptions are powers that only work on living creatures, such as certain Masters like Nilbog, or Panacea's biokinesis.

This effect severely reduces the potential lethality of most powers; most telekinetics can't reach into your chest and crush your heart; most people who can create forcefields can’t create one through the middle of your body and cut you in two; most pyrokinetics can't generate fire inside your brain to instantly boil you, and so on.

For most of the story, the reasons for the Manton Effect are unknown, though the protective tendency of the Effect is well recognized.

Examples

 * A common exploitation of the Manton effect is to have a costume made, whole or in part, out of the subject's hair to prevent the costume's destruction. This is due to the Agent reading the hair as still "part" of the parahuman
 * Powers will ignore walls before they ignore a floor. This is the reason intangibles do not sink into the ground.
 * Vista has the ability to stretch and compress space, but this becomes a great deal slower and requires more effort when the space she is working with is occupied by people, and she is unable to stretch, distort or compress a living individual.
 * The author notes in the comments of Interlude 5 that this is due to Vista's ability involving a great many small, interconnected events through the space she's affecting, and the Manton Effect prevents said effects from occurring inside people, forcing her to work around them.Taliesinskye and Psychogecko are pretty on target. Though Kaiser’s power wouldn’t prevent him from growing armor -on- someone (which is essentially what he did when he trapped Lung in the pyramid of blades, only it was a more offensive use). The Manton effect essentially says that for most capes that does something at point X, or originates at point X, that point X can’t be inside another person. Different capes are affected by this to different degrees or not at all.  Capes like Vista and Faultline are extreme cases of capes who are affected a great deal; Vista’s power affects an area, and it’s exponentially harder to use if there’s more people inside that area. This is mostly because her power is actually lots of little interconnected events, some of which are bound to fall inside people in the area. Faultline’s drawback is that she simply can’t affect another living thing with her power, period, likely because she’s extending her power into whoever or whatever she’s touching to sever molecular bonds and ‘cut’ them.  On the flip side of the coin, for capes with powers that wouldn’t work if they couldn’t reach inside other living things, the Manton effect doesn’t usually apply. Taylor’s one such case. If the Manton effect was as severe in her case as it was for Faultline, she wouldn’t be able to extend her power to the bugs’ minds (such as they are) to control them or get intimate details on their biology and locations… so she wouldn’t have a power at all. Panacea and Regent are other examples of this at work.  In the end, though, scholars in the setting haven’t fully researched and understood the Manton effect and why it exists. So the fact that there’s some confusion on the matter (to the point we may be talking about different effects that are all being (erroneously?) gathered under the same umbrella) is perfectly ok. -  Comment by Wildbow in Interlude 5
 * Bakuda, by contrast, researched Vista's powers and found a way to create a controlled distortion of flesh, and specifically references the Manton Effect when explaining this.
 * Faultline can cut through objects with a touch, but can't cut through living things - even plants.
 * Sundancer is never burned when she summons her eponymous sun. Instead, temperature completely normalizes in a set distance around her.
 * Crusader has a favorable Manton limitation. His ghost duplicates are unrestrained by inanimate objects but will interact through living objects; this allows them to stab through armor. These replicas could also lift him into the air, giving him a limited form of flight.
 * Rune could not lift 'living' objects.
 * Damsel of Distress clones, surprisingly, are immune to each other powers, despite it being less merciful about their hair and clothing than usual.
 * A similar but unrelated effect are Sechen ranges

Bypassing the Manton Effect
The most common way for a parahuman to bypass the Manton Effect is to undergo a second Trigger Event.

Faultline surmises that the Manton Effect might be a mental block set in place when an individual gets their powers, protecting them from hurting themselves with their abilities, which is overgeneralized to include all living things rather than just the user. Her attempts to retrain and circumvent this mental block, however, prove futile.

Bakuda was able to partially bypass the Manton Effect when she created a bomb based on Vista's abilities, which are normally Manton-limited.

Origins
The Manton Effect is a result of a person's shard imposing limitations to ensure they don't accidentally hurt themself. During a second Trigger Event, the shard can refine its technique to only protect the host.

This desire to protect the host is also why there is a tendency for parahumans to have a minor Breaker ability protecting them. Host protection measures misfiring in a miscalibrated shard is responsible for Case 53 mutations.

A hard-coded Manton Limit common to most powers is that they do not commonly operate in Space. This is partly to prevent Parahumans from moving so far away from their Shard that transmitting power to them becomes a hassle, and partly to prevent the host species from using their powers to escape the planet.