I need to know EXACTLY how lighting affects combat, and if it does at all. It's listed in the DMG as just an explanation of an environmental thing, but how does it work specifically?
Does Dim Light or Darkness affect attack rolls and how? I've heard that Dim Light causes a -2 penalty, and Darkness inflicts a -5 penalty, on anyone with normal sight. WOTC refute this as incorrect.
How does Dim light or Darkness affect concealment? Do they add to the roll? Do they allow concealment to occur? Do they automatically grant concealment?
Two fighters and standing side by side taking swings at each other. One is standing in Bright Light, the other in Dim Light, or Bright Light/Darkness, or Dim Light/Darkness. Does one have an advantage over the other?
I need to know what exact mechanics occur in these circumstances, if any.