Clay attack stone

The Clay attack stone can be made using the Construction skill at level 39. The Clay Attack Stone has 400 life points, and it does not attack you. This is an ideal Combat training dummy, however do not expect to gain combat experience from it. A player only obtains one experience for every clay stone shattered. Sometimes, though, a piece of clay will fly off and hit you in the face, dealing damage, usually 30 or 40 life points. Once defeated, you may right-click and select "Activate", and it will regenerate, allowing you to fight it again. You may only make one Clay Attack Stone in your house. When activated, it appears as a yellow dot on the Minimap. When a player tries to cast stun or any other stat-lowering spell on it, the chat displays "You can't attack this npc."

The life points seem to alternate. In one round, each person gets their own batch of life points to knock down. The person who does 400 points of damage faster than the others, wins. In the second round, the life points are communal, and the person who takes off the last few life points wins.