Here are all the relevant FAQs for Darkness:
No, sunrods can never increase the light level of an area of darkness because they are not magical sources of light. In such an area, it automatically defaults to the ambient natural light level (the light level from natural sources, such as the sun, moon, and stars—not torches, campfires, light spells, and so on), and then reduces it one step.
No. Nonmagical light sources do not increase the light level within the spell's area, regardless of whether the light source is in the area or outside the area.
No. If a darkness spell reduces the light in the area to actual darkness (or supernatural darkness, if using a more powerful spell), you can't see through the darkness into what is beyond it.
Now, here's the scenario:
If someone with regular 60' darkvision is trying to find enemies that are on the opposite side of an area of Darkness and outside the radius of the darkvision, but are carrying torches.
Can the creature with darkvision see the enemy carrying the torches?
I'm gonna go with depends.
Does the darkness area cover completely all angles between the torches and the darkvision user?
Example:
10 foot tall corridor - 10 foot wide - 100 feet long - torches at one end - darkvision person at the other - darkness in the middle.
Answer - no
Example2:
Cavern - 100 feet tall - 100 feet wide - 100 feet long - torches at one end - darkvision person at the other - darkness in the middle. I'd say yes - and the residual glow from the torches would actually 'outline' the darkness area making it look like a rainbow-ish shape of light.
A single candle is visible 1.5 miles away in the darkness by the common eyeball - yes it may not give 'visible' light (enough to see by) but it's very very noticeable in the dark even if you can't make out 'what' it is.
Ckorik,
The cavern we were in was wider than the 20' radius, but not higher.
In this case, the torches "dim light" radius does not reach past the darkness area of effect.
Ckorik,
The cavern we were in was wider than the 20' radius, but not higher.
In this case, the torches "dim light" radius does not reach past the darkness area of effect.
I hear you - however the answer is going to define your game and how your players will react to your game. The question is: Do you use mechanics end stop - or do you use mechanics and a bit of common sense where the mechanics end?
The answer you give is important and something you should stick with in the future regarding how to react to things when your players use the rules against common sense - which happens - alot. Take this example. Light a candle in a pitch black room with no windows. How large is the 'visible light distance' (the throw as it were). Now imagine this is a basketball court - there is a short distance at which the candle is no longer usable to see by.
Now have someone else hold the candle - and go to the other side of the court - where they can't see you at all using the candle light. Can you still see the candle? The game rules don't cover everything - the 'dim light' radius is a game mechanic to give you a hard rule for an approximate thing which is 'how far can I see using this light source'
Magic changes this - in that it creates hard and fast rules for how the light reacts - point of fact - a light spell is safer than a torch in a dungeon because it's radius is a *hard shell* just like darkness. A Torch however is natural light - as such it is visible from a much much larger area than it's visible light spreads. And in that scenario you outlined I would have an 'aura' around the shell of the darkness because the magical darkness is *so* absolute that any ambient light from either side is going to be a *dramatic* opposition to the magic.
However if you want to use the rules and not add those types of situations - in that case outside of the usable radius of a candle - even without magic - someone shouldn't see the flame. Just be ready for the players to use 'but the rules say...' as an argument back at you.