A proposed idea for game of dwarves where there are 3 main rooms surrounded with unbreakable rock (besides the player's encampment and the normal event rooms). The players must mine down to them and open them to unlock the chests inside to gain the ability to research next tier of soldiers and unlock items for their base. However, after the chests have been open for 5 minutes, the room begins spawning enemies. The closest room to the surface Spawns mildly tough enemies, the second, harder, and the third hardest. All coming in waves and assulting your fortress. To win seige mode, the player must open all three chests and find the crystal located somewhere on the map in another impenetrable room with a 1-square enterance containing a boss.