Legns

Legns are a fictional class of nanoscale agents featured in speculative fiction and game lore. They are described as distributed, self-organizing systems capable of influencing physical matter and biological processes at micro scales, without a central controller. In most depictions, legns operate as programmable modules that can be deployed to monitor ecosystems, repair infrastructure, or remediate pollution, while remaining largely invisible to unaided observers.

The term legn is typically treated as a plural; a single agent is a legn. The etymology is often presented as a neologism derived from elements of words like legacy, legible, and nano, though exact origins vary by author. The concept first appeared in early 22nd-century fiction and has since appeared in multiple media, frequently used to explore themes of autonomy, control, and the interface between technology and nature.

In-world properties commonly cited: decentralized networks with local decision-making, strict fail-safes and self-limitation to prevent unintended effects, energy requirements drawn from ambient sources, and a tendency to blend with surroundings to avoid detection by non-target organisms. They are portrayed as both benevolent administrators of environments and potential threats if captured or corrupted by antagonists.

Legns are used in narratives to examine governance of artificial life, ecological engineering, and the ethics of intervention. While popular in science fiction, legns are not real or scientifically recognized; they function as a literary device to illustrate themes around emergent behavior, modularity, and the responsibilities that accompany powerful technology.