OGL Alternatives: Alternate Advancement System

If you like the genres Fantasy (High Fantasy) , this game is for you.

If you like the mechanics Class Based (Pilot, Wizard, Scientist, etc), Level Based (Earn XP and level up), Dice (Primarily d20), Skill Based (buy or gain skills), Dice (Various), Attribute/Stat Based (STR, CON, PER, etc), Race Based (Player Race/Species affects gameplay), Grid-based (uses square terrain for move/combat) , you will enjoy this game.

This game falls under the category: Sourcebook (rules/options to enhance play), Alternate Rules (Variant Core Rules).