Traits are specific abilities that differentiate each merc and represent their essential being. Unlike attributes and skills, traits can’t be developed or improved later in the game.
Traits can be either positive or negative, yielding a bonus or penalty to a merc's performance. There are two trait classifications: skill based and character based.
The skill-oriented traits indicate which weapons the soldier is proficient in. This advanced skill gives them a 10% bonus when shooting with that class of gun.
Some mercs are experts at handling specific guns and gain a 20% bonus when using with that firearm. Character traits have a wide range of variety that can directly affect their performance, such as the unfit trait.
Other traits can raise or lower morale, which ultimately leads to a plus or minus in their overall performance.
A merc's morale is simply how content or dissatisfied they are. Morale is influenced by several factors, but the most obvious are their traits and their relationships with other mercs in their squad.
Morale is a lot more of an issue than keeping a team of happy campers. Each merc can get a bonus or penalty to all their equipment checks based on their morale. A merc's morale has a default value of normal that has no positive or negative effect on them.
However, it can rise or fall to good, very good, low, and very low. Each tier represents about a 10% bonus or penalty, so a merc who is feeling very good will get a significant 20% boost.