In Diablo 3 runes are used to modify skills that player character has. There are five runes per skill and runes are unlocked by leveling character. In maximum level all runes are unlocked and player may freely experiment with skill and rune combinations.
In Doom there are rune stones in some levels which player may interact with. These rune stones will present player a combat challenge which upon completion will grant player a rune power. These rune powers may also be improved by completing rune specific tasks.