Chief Librarian Mephiston

Unless part of an **attached** unit, this unit is not **visible** to enemy models unless they are within 12" of this unit, and it cannot be targeted by **[INDIRECT FIRE]** weapons unless the attacking model is within 12" of this unit. 
If this ability takes the form **Lone Operative X"**, unless part of an **attached** unit, this unit is not **visible** to enemy models unless they are within **X"** of this unit, and it cannot be targeted by **[INDIRECT FIRE]** weapons unless the attacking model is within **X"** of this unit.

While every model in a unit has this ability, that unit is a **Fights First** unit. 
See the Resolve Fights First Combats step in the Fight phase (12.04).

This ability always takes the form **Feel No Pain X+**. Each time a model with this ability would lose a wound, roll one D6: on an **X+**, that wound is not lost. 

If your Army Faction is **^^Adeptus Astartes^^**, at the start of your Command phase, select one unit from your opponent’s army. Until the start of your next Command phase, that enemy unit is your Oath of Moment target. Each time a model with this ability makes an attack that targets your Oath of Moment target:
■ You can reroll the Hit roll
■ If you are using a Codex: Space Marines Detachment and your army does not include one or more units with the **^^Blood Angels^^**, **^^Dark Angels^^**, **^^Deathwatch^^** or **^^Space Wolves^^** keywords, add 1 to the Wound roll as well.