There is a concept in Swords and Wizardry known as morale in which any creature with a brain will retreat from a battle when they become to scared or do not see the odds in their favor. I typically do this VIA a saving throw +HD. For the most part this works well, however, we never see the players affected by a real sense of morale.
Now let me explain what I mean here, because it is not the same thing as the fight or flight version of morale mentioned above. What I mean is the real sense of morale that humans face on a day-to-day basis. How would that figure into a game in a way that goes beyond roleplaying.
For example El has found out that her lover is cheating on her. Would she be at a 100% when fighting? What of Olaf the bard whose wife wants to file for divorce because she found a much better lover in El’s ex? Or the silent barbarian who finds out he is to be a father?
These are all great from a roleplaying moments. Trials and tribulations are what make the PCs (and people) what they are. However, wouldn’t there be some sort of effect on the character’s ability to perform in any task? Could El, as a mage, be able to hold her concentration when the memory of walking in on her lover and Olaf’s wife keeps peaking into her mind? How would that effect her spell casting? Same for Olaf, would he be able to sing the songs of heroes and kings to aid his allies when his heart is utterly broken?
Oddly, I have no answers for this. The simplest route would be for a positive or negative modifier to rolls that are scaled to the severity of the issues. However I don’t know if such a thing could effectively convey such things. Another route would be to add in some of the FATE mechanics and reward players for roleplaying (even by taking a hit or purposefully missing a target) their plight … that though is a slippery slope and I don’t think shoehorning another rule set into the OSR rule set of my choice is the right direction anyway.
Is this even something should come up in a game? I don’t know. As people who PBP with me know I typically play a complaining old man type (constantly going on about the shear beauty of coffee), but I think I would blanch if my GM decided that my lack of coffee is to affect my rolling.