A weapon that fires pressurized streams of magnetically-responsive ferrofluid that adheres to surfaces and can be remotely activated to form rigid structures, constrict around targets, or generate localized magnetic fields. The Tar Pit turns a liquid weapon into a controllable solid on command.

Axiom Systems designed the FP-3 as a non-lethal capture weapon. The ferrofluid stream coats a target in a thin layer of magnetic liquid that, when activated by the weapon's remote signal, transitions from liquid to a rigid lattice that immobilizes limbs, seals airways, and locks joints. The activation is selective — the operator chooses which portions of the ferrofluid to harden and which to leave liquid, allowing precise control over the degree of immobilization.

The Tar Pit's lethal potential comes from its ability to seal airways and restrict circulation. A full-body ferrofluid coating that is activated simultaneously creates a rigid shell that prevents breathing, and the magnetic lattice can be tightened to restrict blood flow. Axiom classifies the weapon as non-lethal, but the line between immobilization and suffocation is a matter of operator intent.