Goblins, as you may or may not know, are not a particular patient, considerate or generous race. So when vast deposits of riches were discovered in the ground under the great plains, the greenskin clans flooded there, vying to retrieve more treasures than their rival brethren. In their haste, however, the mines they dug and tracks they laid disturbed the fragile foundations of the plains, causing the ground to collapse into a chasm below, burying goblins and jewels alike...
Race your minecrafts against other clans to gather the most jewels before the chasm swallows you up!