Dim light in 5e: what gets disadvantage, what does not, and what darkvision fixes

The three light states in the 2024 rules

Every square on a map is in one of three states. Bright light is normal vision. Dim light, the edge of a torch's glow, twilight or a full moon, makes an area lightly obscured. Darkness, an unlit room or a night with no moon, makes it heavily obscured.

The effects are short enough to learn by heart:

• Bright light: no effect.
• Dim light: disadvantage on Wisdom (Perception) checks that rely on sight.
• Darkness: a creature trying to see something there has the Blinded condition for that purpose.
• Blinded: you fail checks that need sight, your attack rolls have disadvantage and attacks against you have advantage.

Does dim light give disadvantage on attacks?

No. This is the most common misreading at the table. A fighter swinging at a goblin in dim light rolls normally, and so does an archer shooting into it. Dim light only affects Perception that relies on sight, which matters for spotting a hidden creature or noticing a tripwire, not for hitting something you can already see.

Disadvantage on a check also costs 5 from a passive score. A character with passive Perception 14 notices things in dim light as if it were 9, which is why a sentry at the edge of a campfire's glow misses the rogue in the treeline. The 2014 rules read the same on all three light states; what changed in 2024 is Hide, which now sets a flat DC 15 and gives the Invisible condition, and still needs heavy obscurement or three-quarters cover, so dim light alone is never enough to hide.

What darkvision does and does not fix

Darkvision lets a creature see in dim light within its range as if it were bright light, and in darkness as if it were dim light. Two consequences follow. An elf with 60 feet of darkvision in a pitch-black corridor sees the first 12 squares, but as dim light, so Perception checks there are still at disadvantage. And beyond 60 feet the corridor is simply dark.

Darkvision also sees darkness only in shades of grey, so colour clues vanish. It does nothing against magical darkness such as the Darkness spell, which blocks darkvision outright, and nothing for the half of the party that lacks it. A mixed party in a dungeon still needs a torch, and a torch gives away its bearer from far beyond its own light.

Unseen attackers and targets

Attack rolls change only when someone cannot see. If you cannot see your target, you have disadvantage; if the target cannot see you, you have advantage; if neither can see the other, the two cancel. Two creatures fighting in total darkness without darkvision roll normally, which surprises players who expected chaos.

This is where light becomes tactics. A party with darkvision fighting creatures without it can put out the lights and gain advantage on every attack. A group of cultists holding the only lantern is lit for everyone's archers while they peer into black. Put the light sources on the map and let the players decide what to do with them.