The Nephilim, or Nephil for short, are a race of feline humanoids in the game series Exile and its remake Avernum, set largely in the underground world taking the same name. Most live underground after being sent there by the human Empire, who rule the surface world. Some still survive on the surface, albeit constantly hunted by xenophobic Empire troops. As a result, the majority of Nephilim underground and on the surface are hostile towards humans, though some do get along and even live amongst them.
Nephilim are one of the three playable races in the series — the other two being humans and Slithzerikai — and typically serve as a low-level enemy for the player's party to fight, though their role becomes more complex as the games progress. While Nephilim society is rarely explained in depth, much can be gleaned from the in-game descriptions and comments by NPCs.
 General information
Nephilim were once common on the surface, but are now mostly extinct due to the Empire's genocide. Most survivors live in the underworld known as Exile (or Avernum in the remakes). Nephilim live in clans, usually consisting of a single village led either by a chieftain or shaman. They are generally wary of outsiders and prefer to avoid contact, mostly due to the Empire's oppression.
Some Nephilim are barbaric in nature, attacking humans without provocation. They are portrayed as worshiping dark beings, and possibly demons, though none are mentioned in particular. They are also known to torture and execute prisoners and slaves. Goblins tend to be the most commonly-kept slave, though — while not seen in-game — humans are also enslaved. Most Nephilim seen in-game tend to be evil in nature, though as the series progresses these seem to decline in number.
Some Nephilim more or less get along with humans, some even living among them. In a few instances they can be seen running shops in towns or offering players quests. While the player's party does encounter several friendly villages, each is a world map event and is not treated like a normal town, leaving the Nephils without the equivalent of the Slithzerikai town of Gnass.
Nephilim are extremely agile and dexterous, quicker than any other race in the game. They often have archers with them, and their warriors often carry javelins. Even with their advantages, they are also capable of being as strong as any other race in the game, though far fewer are mentioned to be like this. Nephilim in-game graphics and sprites tend to portray them as slightly shorter and thinner than other races.
Sometimes a newborn Nephilim is born bigger, meaner, and sterile. These are known as Nepharim. Nepharim retain all the advantages of their Nephilim cousins, as well as their increased strength and toughness, though they are fewer in number and much more reclusive, often separating themselves even from their smaller cousins.
Nephilim and Nepharim generally do not get along. While on occasion a Nepharim may be leading a Nephilim clan, more often they seem to fight amongst each other. This is most evident in Exile/Avernum 2 where a tribe of Nepharim has enslaved an entire Nephilim clan. A Nephilim NPC in Avernum 2 mentions that he loves all of his children, even the Nepharim, which suggests that Nephilim parents generally cast out Nepharim children.
 In-game details
- Spoiler warning: Plot and/or ending details follow.
In all but the original Exile and Avernum, the player can add Nephilim to his party. In the Exile series, Nephils get a dexterity bonus but a 10% experience penalty. In the Avernum series, Nephilim get bonuses to bow and throwing skills, sometimes get additional move points, may get their turn sooner in combat, and are harder to hit, while retaining the 10% experience penalty. Having a Nephilim in the party will cause several NPCs to react differently. Some may dislike them and refuse to help the player, while others may help because they have a Nephil.
The Nephilim are primarily an early game foe, as relations between them and humans have not yet smoothed out. They are sent down to the underworld by a different portal, though where it is remains unknown. Almost all of the Nephilim encountered in the game are hostile, and will attack the player's party on sight. The barbaric Nephilim are highly organized and their only desire is to slay all humans and take over the caves, though they are not as numerous as those Slithzerikai with the same goals.
- One of the first optional quests in the game is to slay the chieftain of a new Nephilim fort being constructed by goblin slaves.
- The first main quest sends the player to the Nephilim's main fortress to retrieve an amulet stolen from the mayor of Formello.
- One of the later early game quests has the player rescue a group of prisoners from a Nepharim fortress.
- During a mid-game optional quest to slay an ogre mage, the player has the option to free a group of Nephilim from prison. While they are hostile, they have only have the energy to hiss at the player and walk by as they are released.
- In a late game optional dungeon, the player's party becomes trapped inside the giant's fortress. Two fellow prisoners, a human and a Nepharim, advise the party on how to get everyone free.
 Exile/Avernum 2
When the Empire invades the underworld, most humans — or, more specifically, the Exiles/Avernites — generally get along with the Nephils, working together to fight a common foe. There are many more Nephilim for the player to interact with, and they may even be included in their party. Some Nephilim run shops in the game as well. However, not all are friendly. Some refuse to make peace and continue to harass humans, while others have taken up careers as brigands.
- Fort Ganrick, the game's starting location, comes under attack from hostile Nephilim very early on, though this battle can be avoid entirely if the party uses a different entrance/exit than the main gate.
- The first optional quest in the game is to slay the Nepharim chieftain of a group of barbaric Nephilim who took over the mines.
- One of the optional quests late in the first chapter has the player sent to destroy an altar used by crazed Nephils to make undead. The altar is located in the ruins of the smae fortress the player was sent to in the first game when recovering the amulet for the mayor of Formello.
- An optional quest early in the fourth chapter has the player slave the chieftain of a Nepharim clan and rescue to the enslaved Nephilim in order to secure help from the local clans.
- Another optional quest early in the fourth chapter offers the player the opportunity to cure a mysterious disease afflicting a clan of Nephilim near Mertis by giving them graymold salve. Doing so will lead to the other clans near Mertis becoming eager to help the player by offering to sell them potions, magical charms, or to train them in the bow skill.
 Exile/Avernum 3
Nephilim are rare on the surface due to the Empire's genocide. Having a Nephilim in the party results in many more combat encounters with local militia, discriminating guards, prejudiced townsfolk, etc., especially in the Avernum remake. A number of NPCs may also withhold help. On the other hand, a Nephilim allows the player to avoid combat with other Nephilim, and sometimes receive aid from the few tribes there are. Despite the hatred, some Nephilim live as shopkeepers in the more tolerant surface cities.
- In Upper Exile/Avernum, some hostile Nephilim bandits roam around, but have no base.
- The goblin tribe in an early optional dungeon is apparently led by a Nephil, as one is present in caves that the game describes as cleaner and more luxurious, though it does not explicitly say the Nephil is leading them.
- In an outdoor encounter in Southern Valorim, the player has the option to save a group of Nephilim from a group of ogres.
- On the Island of Bigail, the player can help a Nephil recover a charm important to the feline's honor.
- In Central Valorim, the player can help defend a Nephil settlement from troglodytes.
- In North Eastern Valorim, a there is a lone Nephil who will train the party in the bow skill.
 Avernum 4
There are far fewer hostile Nephilim in the underworld. Those who remain are primarily bandits, though there is one barbarian clan the player has to deal with. There are many more Nephilim NPCs around as well, now commonly seen in merchant caravans, with travelers, adventurers and other small groups. As always, some still run a few shops.
- One of the few remaining barbarian clans, the Longtails, took over a checkpoint and blocks access to Fort Draco. The player has to fight through them in order to advance. Slaying their chief is also an optional quest.
- During the first main quest, there are a number of mind-controlled Nephilim who will attack the player. Slaying their master will set them free, causing them to no longer be hostile.
- A mid-game optional quest sends the player to find a nepharim bandit fortress in the Honeycomb. Another optional quest given by a Nephilim named Arrwm has the player kill its leader, Hosharr.
- Later in the game, an optional quest has the player hunt down a half-breed Nephilim bandit. Exactly what the other half is, the game doesn't say, though based on the physical description it may be human.