Assume we have a combat taking place in a big, open, flat field with no furnishings, so we're just dealing with the characters themselves. In this case, how does cover work?
Do enemies provide cover from the heroes for other enemies? Do friendly allies provide cover from enemies for each other? Do size or status effects affect anything? How much cover is granted (½, ¾, full) and for what things? Can anyone Hide (halflings?), and what does that help with?