Kangaroo effect

The Kangaroo Effect is a visual technique for displaying art on dark boards outside the field of vision of the player entity. For gameplay reasons, torches, passages, and the player are unconditionally visible on dark boards. By placing large quantities of these entities with the same foreground and background color, one can depict inaccessible regions as solid bodies.

A precursor to the effect is found in some early ZZT worlds, where plain brown-on-black torches are used on dark boards to suggest a thick forested area.