Birthright is a Dungeons & Dragons setting, where players are intended to be the rulers of large realms and receive special powers from their heritage. In the distant past, there were a large number of gods, one of whom was evil and tried to conquer the world. The other gods assembled a large army and fought him directly, then blew themselves up to kill the evil god, creating a bunch of new gods and granting mortals bloodlines that gave powers based off the original god who they drew the power from. The guys empowered by the death of the evil god are called blood abominations and are invariably evil.
This setting provides examples of:
A God Am I: Happened at Mount Deismaar after the original Gods duked it out. Their champions inherited their power.
Big Bad: The Gorgon. He was the strongest of the evil god's followers, but was too far away from the explosion to become a god, so he ended being the most dangerous Awnshegh instead.
Can't Argue with Elves: Formed a Wild Hunt to kill humans, one Elf is known by the title Manslayer.
Loads and Loads of Rules: The campaign themed itself on allowing Players to run PC's who ruled a domain(country, temple, guilds), which required more rules.
Meaningful Name: As the Pcs are often rulers with a ancestral bloodline, or birthright.
Mirror World: The Shadow World, same as the real one, except inhabited by the dead.
Our Monsters Are Different: Many monsters that are common Mooks in regular D&D are unique villains called Awnsheghlien or Blood Abominations. (Examples: The Gorgon, the Hag, the Manticore.) They often spawn mook versions as well. While other Bloodlines are less contagious, they are also known to "enhance" normal animals: "Bloodhounds" descended from war-dogs who got spilled power can detect Shadow creatures and tend to be very smart, loyal and strong. Wild dogs with the bloodline of a war-god become natural leaders in their packs just like humans do, and can be really nasty critters — or legitimate bloodtheft fodder, for those who can pull this.
Our Vampires Are Different: The vampire is a blood abomination who used to be a heroic nobleman, but stabbed a previous blood abomination in the heart and got his bloodline.
Power Parasite: Some of the raw bloodline strength, sometimes along with abilities, can be stolen by killing its carrier in specific ways. Blood Abominations tend to be very, very powerful because they frequently choose bloodtheft as the road to power and actively seek it — by the time people knows of them, they usually already have slaughtered and drained lots of "blooded" folk.
You Kill It, You Bought It: Kill one of the Blooded by violence, and his spilled power will be inherited by anyone in the vicinity of his death. Kill him with tighmaevril, or by piercing him intentionally through the heart, and you get it all. But since a bloodline may dominate equal or weaker one, the killer sometimes get more changes than just power. Which is one of reasons why Awnsheghlien are hard to eliminate: those who slay one without being more powerful as scions frequently end up tainted by its bloodline, possibly producing several unwilling "heirs" from one killing, eventually turning into new overpowered monsters.