I noticed that each soldier gets different will bonuses every promotion. Does this depend on something specific in the mission such as kills or actions, or is it completely random? Does every soldier have their own predetermined will bonuses?
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What I have seen is that all rookies start with a will of 40 (from my limited sample size at the start of the game). Once you get the "new guy" perk that allows specializations for new recruits their will can get bumped anywhere from +1 to +10 points (up to 50 is the highest I've seen on a soldier with 0 missions). From there, every rank seems to grant some amount of will points which either differ by soldier or by something else.
I'm wondering if some soldiers are just more gifted than others and generally get larger bonuses or if it's something mission specific that determines it. I have a colonel that has a will of 90 and another that has only 75. Now, some of this is probably due to the perk that grants larger will bonuses, but I haven't seen any numbers on this. Any info related to will progress would be great. I'm trying to build a psi army.