 Only if the last play inside the area would kill the enclosing group, thus freeing one or more liberties for the group that filled the space, can the play be considered.This can only be achieved if the liberties on the outside of the enclosing group have been covered first.Thus, enclosing an area of one or more liberties (called an "eye") can make the group harder to kill, since the opponent must cover all of its external liberties before covering the final, internal liberty.