A lamp and two lanterns are described on page 152 of the Player’s Handbook as follows:
Lamp. A lamp casts bright light in a 15-foot radius and dim light for an additional 30 feet. Once lit, it burns for 6 hours on a flask (1 pint) of oil.
Lantern, Bullseye. A bullseye lantern casts bright light in a 60-foot cone and dim light for an additional 60 feet. Once lit, it burns for 6 hours on a flask (1 pint) of oil.
Lantern, Hooded. A hooded lantern casts bright light in a 30-foot radius and dim light for an additional 30 feet. Once lit, it burns for 6 hours on a flask (1 pint) of oil. As an action, you can lower the hood, reducing the light to dim light in a 5-foot radius.
In real life, these devices have a way to adjust their wick to put out their flame. However, the phrasing of “Once lit, it burns for 6 hours on a flask (1 pint) of oil” made me wonder if the intent was to only allow them to burn for the full 6 hours. That would probably consume the oil more quickly than necessary — especially if your party has darkvision — but it does have the benefit of not requiring anyone to track the consumption of fractional pints of oil.
I then realized that the same argument could be applied to candles (pg. 151):
Candle. For 1 hour, a candle sheds bright light in a 5-foot radius and dim light for an additional 5 feet.
When I first read this, I assumed you could blow out and relight a candle at will, but I now wonder if, once you light a candle, it’s consumed. Otherwise you’re tracking fractions of burned candle.
And then there’s the torch (pg. 153):
Torch. A torch burns for 1 hour, providing bright light in a 20-foot radius and dim light for an additional 20 feet. If you make a melee attack with a burning torch and hit, it deals 1 fire damage.
In this case, based only on my impressions from fiction, I had assumed the torch had no way to douse it without making it unsuitable to be relit (like dunking it in water or covering it in sand or dirt) — but maybe that’s not true.
As far as I can tell, the PHB doesn’t describe any way to routinely put out any of its non-magical light sources, so my question comes down to these:
Does this lack of description mean the light sources can’t be put out — or, at least, that if they are put out before their duration is over, they’re nonetheless fully consumed?
Or is being able to put out these light sources an assumed part of the normal functioning of the universe, just like all the other normal things that aren’t explicitly stated in the rulebooks?
Or do groups follow one option over the other based on their attitude toward resource management? Those who track every last ration and arrow also track fractional oil pints and fractional candles, but those who don’t, don’t?
Or have I missed something else entirely?
Somewhat related, from Pathfinder 1e: Can incendiary arrows be put out and re-ignited?