From publisher blurb:
A classic fantasy adventure game in the style of the earlier days of the worlds oldest roleplaying game. Although it mimics that style it is built upon the modern mechanics of the Shift7 Game System, a player facing system, where the players make all of the rolls. The Shift7 system uses a small dice pool of 2 to 3 dice (1d20 + Attribute die and maybe plus or minus a single d6) with no static modifiers (no more +1's or -1's), this speeds up play and provides a cohesive system that allows both GM and Players to easily come up with solutions for any attempted action.
Oldegrave is highly compatible with OSR adventures, and with minimal conversion you can easily adapt and use any classic adventure modules you own. If monsters have a size and HD you are ready to go.