A land mine is an item used in the variation of Monster World included at the end of volume 6 of the manga.
The game master can place up to five land mines on the board, by marking them in the field check sheet. They cannot place landmines in squares adjacent to monsters or other land mines, excluding diagonally adjacent. The hero does not have access to the field check sheet and consequently does not know where the land mines are located. If the hero lands on a land mine, they lose 100 Hit Points.