HEX (Piet Hein-1942) could be the perfect abstract board game. It has the simplest rules of almost any known game, yet is remarkably difficult to play well. nestorgames portable 11x11 HEX set contains 120 discs in two colours (red and blue). The discs are 15mm diameter and 5mm thick.
With this set you can also play Dhex, by Néstor Romeral Andrés.
You can also purchase the 14x14 edition here.
And you can also try the Java version here!
Rules not included. But you can access them by clicking the 'Rules' button below.