Bravery
The Bravery stat is a measure of how brave a unit is in the face of danger. A higher bravery score reduces the amount of Morale lost due to morale-decreasing events, so a brave unit (alien or X-COM) has less likelihood of panicking or going berserk during combat.
Stat Range
New X-COM recruits will always begin with a value between 10 and 60. Due to the way the Bravery stat is stored in the data files, it will always be a factor of exactly 10. X-COM soldiers' Bravery is capped at 100, although tanks and certain alien races can have a Bravery of 110. Unlike other stats, Bravery cannot overflow its cap because it can only increase by one unit at most per combat mission.
Improvement
When a unit's Morale drops below 50, it has a chance of panicking or going berserk (see Morale#Panicking_and_Berserking for full details). If a unit successfully resists panicking, it will gain a "bravery experience" point. For each bravery experience point gained during a combat, a unit will have an additional 10% chance of gaining a point of Bravery at the end of the mission, up to a possible 100% chance with 10 (possibly 11) bravery experience points.
Bravery Traning
Your soldiers' Bravery can be trained easily and safely once you have completely secured a mission field, particularly after your troops have received Psionics training. Capture (i.e, Mind Control) one or more psi-enabled aliens (Ethereals or Sectoid Leaders/Commanders) and box them into a corner (or the Avenger) so you can shoot them later. Fully disarm the aliens using the inventory trick, and have all your soldiers drop all their weapons and grenades as well so they don't kill each other.
- Now you can hit the End Turn button repeatedly while the aliens go to work on your psi-weaklings. Soldiers with a Psi Strength of 80+ seem to be immune to psi attacks (use them to wall the aliens in), but all others can be trained. In addition to possible Bravery gains, bravery training can also trigger secondary stat increases. See Experience#Secondary Stats for more details.
- Move any soldiers that have been psi-attacked repeatedly as far away from the aliens as possible to give less psi-weak soldiers a chance to get trained. Aliens will favor attacking psi-weak soldiers, but also focus on nearby soldiers. They also cannot mind-control soldiers past a certain distance, so move your weakest soldiers to a distance where they can only be panicked, not controlled. You may need to mind-control the aliens periodically in order to regain control of your troops so as to move them away.
Bravery and Psi Attacks
Psionic panicking attacks will reduce a target's morale by an amount dependent on the unit's Bravery. Although high Bravery will not make a unit more psi-resistant, particularly to mind control, it can greatly reduce the impact of panicking attacks performed on that unit. See Morale#Psionic Panicking Attacks for full details.