BLISS is a mnemonic used in US evasion training to select and camouflage a concealed place to stay. The five letters stand for Blend, Low silhouette, Irregular shape, Small and Secluded location. Together, they help assess how conspicuous an isolated person's position is while they are trying to avoid detection and capture.
The five characteristics
| Characteristic | Meaning for the site |
|---|---|
| B · Blend | The site fits the surrounding terrain and vegetation. Conspicuous changes to the surroundings work against this aim. |
| L · Low silhouette | Its profile stays low instead of standing out above surrounding features. |
| I · Irregular shape | Its visible shape should avoid conspicuously regular outlines that could reveal the site. |
| S · Small | The site occupies only the space needed. Unnecessary expansion increases the area that must be concealed. |
| S · Secluded location | The location is isolated, away from populated areas and likely routes used by other people. |
An existing concealed position that needs little alteration may meet the criteria better than an elaborate shelter.
The person, equipment and site
During evasion, a concealed stop allows personnel to assess the situation, conserve strength and prepare their next action. BLISS focuses attention on the site's appearance and location. Camouflage also involves the person and their equipment: inconspicuous surroundings cannot compensate for a recognisable body outline, shiny objects or unnecessary movement.
Approaches must remain observable, a way out must be available and concealment from above also matters. The article on evasion hides, hide sites and hole-up areas explains how these criteria relate to rest, reassessment and further movement.
Wording variants and limits
US terminology also uses the expanded wording Blends in, Low in silhouette, Irregular in shape, Small in size, Secluded. It describes the same five characteristics.
The mnemonic focuses on visual conspicuousness and site selection. Site selection must also account for noise, movement, possible location through radio transmissions, thermal imaging and other sensors.