In a Standard Sci Fi Setting, when an interplanetary conflict occurs, it is often three-way and involves:
- The humans. You might have heard of guys somewhere. They are whatever humans usually are in sci fi settings.
- The aliens. They are usually humanoid and very high-tech. Their technologies commonly employ robots, energy control, psionic powers and so on. What they seek from humanity is slavery, obedience, territories and resources. In other words, they want to conquer.
- The monsters. They can be aliens as well, but aren't necessarily so. They are very rarely humanoid, their technology is mostly organic, they are often mutants or a hive mind species. What they want from humanity and just about everything else is proteins, fats, sugars and water. In other words, they want to eat.
- Starcraft has Terrans, Protoss and Zerg.
- Warhammer40000 has Humans in Imperium and Chaos (the human half of it), Aliens in Tau, Orks and Eldar, and Monsters in Tyranids and Necrons.
- Maelstrom has Remnants, Ascension, and Hai Genti.
- Alien vs. Predator has Predators as Aliens, and Aliens as Monsters.
- Giants: Citizen Kabuto has the Meccaryns (Humans), Sea Reapers (Aliens), and Kabuto (Monster).
- Halo would fit this, as you have Humans vs. The Covenant (aliens) vs. The Flood (Monsters)
- Mabinogi has humans, giants and elves as Human, Fomors as Alien, and savage/Fomor-controlled wildlife as Monster.
- Monsters vs. Aliens.
Hello, Unknown Troper. You'll need to get known to lend a hand here.