Beyond the obvious something that seams real, realism in games is a hard feature to hit.
In some cases, things that are completely impossible in real life are seen as realistic by gamers. For instance, in some FPS you can survive being hit by a fair amount of bullets when in real life one is enough, Newton-defying car drifts, etc.
So, in some cases, reductions of life-like actions or consequences implies a bigger sense of realism.
The root of this pseudo-philosophical question lies in:
I am going to create a engine for battles in an online (browser-based) strategic game. Browser-based means that the battle would not be seen. And i do not know how to approach this realism issue.