Elven Commander’s Chessboard

Chessboard made of quartz, basalt and cedar.
Chess pieces will slaughter each other and mend
after every game. Requires 2 players: Both roll 1d20+Int Mod. The highest score wins, attuning player to board. Nothing happens on a stalemate
(same score +/-1). Each successive win adds +1 to
base Int. for 1 hour. 25 successive wins: perma-
nent +1 Int. to base score. Chess pieces will obey
one command from owner out of game for 30
minutes (entire team is a tiny construct.) 3 charges/day to play.