1. A computer system, for assessing life and death in a game of Go, the system for assessing life and death characterized in being provided with: an input-receiving unit configured to run under control of a CPU of the computer system for receiving information concerning a board of Go-game from a storage device of a playing system; an assessment unit configured to run under control of a CPU of the computer system for assessing whether a target stone is alive or dead; and an output unit configured to run under control of a CPU of the computer system for outputting a result of a life and death assessment in the assessment unit, the assessment unit receives input designating at least one of the target stones; specifies points on a board where an outside perimeter of an outside perimeter area and a board edge are separated by no more than a predetermined distance; expands the assessment area in a direction of the outside perimeter area according to a distance of separation between the board edge and the outside perimeter, thereby revising the assessment area; and determines, when any stone in the revised assessment area has escaped, an assessment of said any stone as being alive in cases where said any stone is a target stone, or, in cases where said any stone is not a target stone, executing a process for assessing life and death in which a condition is added that the target stone linked to said any stone is alive, where said any stone is considered to be uncapturable.