... the minor tyrants who use violence and coercion for men to fight a battle they want no part of,
... never seeing or going home,
... being sold into slavery,
... the close quarters of ranks compressing in battle or moving,
... the blow that will come from nowhere,
....screams of men slaughtered like animals,
... being crushed and trampled,
... being maimed and crippled,
... being trampled or smashed by a wild animal or a stampede of men,
... the hunger and suffering of the march and camp,
... the exposure to the elements,
... the disease and dysentery ,
... uncertainty of numbness from Fatigue, wounds, or illness ,
... failure, defeat and execution,
... reputation and honor lost,
... fear for the life of the man beside them,
... for their tribe and home,
... loss of friends and loved ones,
... The gods and being damned, etc...
Every fear thoroughly explored and visualized in the narrative and every tragedy contemplated makes for a good war campaign (or adventure) .
Every pain as well, the loss, starvation, thirst, ache, loss of innocence, etc. I guess expanding the ways to describe and reimagine these all enhance the game.
The focus or mastery of the negative aspects. The ideas I instinctively shy away from but need to explore to humanize and give war, adventure, violence, and killing proper context.
Currently working with the techniques above to enhance immersion, techniques to frame tragedy effectively or unexpected success, and consequences that pull in opposite directions until confusion.
Edit: to implement the techniques above what I would do is take the awareness I have of their fears and focus on it. Remark about the fear and how people react to it. That in war or in an environment of violence this is what drives them and all the stories of how crazy and irrational it makes people. Work with the observable fear in its subtle cues and consequences.
Ex. Many non warriors are forced to fight and you can see their button welding sergeants and corporeal hovering nearby.
Proceed next to ask the player what his character stands to fear from this situation. Or to start small as him what he empathize the fear of the man next to him.
Just a couple of times per session check for what situations make the PC nervous and if they would express it in their decision making. If the player still does not feel it from the environment to translate to PC, the frame in the negative and emphasize on risk. I will have multiple articles on framing if it is asked or needed.