Slysum

Slysum is a term used in speculative fiction and design discourse to denote a hypothetical material or resource with extraordinary properties. It is not a real substance or asset in the scientific record, but it appears across books, games, and theoretical discussions as a device to explore advanced technology and resource economics.

The name slysum appears as a portmanteau of “sly” and “sum,” or as an invented label, and authors use it to evoke secrecy, clever engineering, or a composite that unlocks powerful capabilities.

In fiction, slysum is typically described as lightweight yet exceptionally strong, with high energy density and superconducting or self-healing properties. Some portrayals grant it luminescence, tunable metamaterial characteristics, or zero-point energy. Variants differ on stability and abundance, ranging from highly unstable, cache-like reserves to ubiquitous but guarded supplies.

In narrative media, slysum often powers starship drives, reactors, or advanced computing, enabling rapid space travel or pervasive smart infrastructure. In games and tabletop settings, slysum is a scarce resource used to trade, craft, or unlock abilities, creating strategic tension.

Critics view slysum as a versatile plot device that can streamline world-building yet risks overshadowing plausible science. Proponents note its value for analyzing resource governance, extraction ethics, and the impact of rare materials on technology.