Had a bit of an issue with this spell in a recent session I was Dm'ing. The thing one of my players was contesting was that the line of Sunbeam can be manipulated to bend and turn, as long as it doesn't stretch past the 60ft length. It was my understanding of the spell that the line is a straight line without curve or bend. Now, being the DM, I understand that I can rule one way or the other for flair. However...on paper...without DM manipulation...what is the true ruling? A straight line or a line that can curve/bend?

Your interpretation is correct, a line in a spell description means a straight line. See also https://www.dndbeyond.com/sources/basic-rules/spellcasting#Line

Had it meant to say "curve" it'd have said "curve". There is no spell in 5e that can be used in a curve, although there are some other spells that allow fairly precise control over their AoE shape. Sunbeam is not one of these spells however.

Thanks for the reply. It's always good to get another view on a spell. It certainly felt that Sunbeam would be rather broken if one could direct it along any type of 60ft lined path.

Happy Gaming! ;)

I would like to know if the spells line lasts until your next turn or if it is just brief instant of light = for purposes of giving disadvantage to sunlight senstive creatures

The line is only a flash, but the motes in the caster's hand shine light extend 60 feet (30 bright + 30 dim) and is considered daylight so it will affect sunlight sensitive creatures.

If you ask me, beams don't curve bro

For theatrics a evocation wizard with an ally in the way could cause the beam to curve around them (since he can it not effect his allies)

Other then that a beam is a beam is a beam

The only true way I could see it being "curved" would be by using mirrors and bouncing it around a corner but it would be left to your discretion on whether or not to reward that inventiveness.

Back in older additions, some spells like lightning bolt did bounce off walls, traveling until it reached its maximum length. What was annoying was calculating the path of said line and what squares were or weren't affected by it. Heck, fireball filled an area with its volume, letting players increase its effective radius by putting its center on the floor.

These methods slowed down gameplay and made spells very hazardous to use in enclosed areas, and I prefer how they were dropped in favor of simplicity.

This is one of the best spells to flavor using material components. The actual spell is just to create the mote, the action is to focus it with the magnifying glass. Or you might use an arcane focus or druidic focus. In which case ignore this.

So a Moon Druid can cast Sunbeam and then bonus action Wildshape into a spider or flying creature, and spend the rest of the fight shooting eye-beams from the ceiling? :D

Sorcerer X/Fighter 2. Quicken the sunbeam, use your action to cause the damage again, action surge for a 3rd attempt. It'll end up doing 18d8 radiant damage in a 60ft line requiring 3 saves or the targets would be blinded for a round.

Also works with: 

- Witch Bolt

-Max's Earthen Grasp*

-Call Lightning*

-Vampiric Touch*

-Watery Sphere

-Telekinesis

-Eyebite*

-Sunbeam*

-Investitures of ______

-Project Image

* = better ones. 

Since this spell shoots a ray of light...  and light passes through invisible things because of how light and vision work..  It follows that this spells has no effect on invisible creatures, and can be fired across walls of force (being that they are invisible)...  ???

It would still cause damage. Light passes through objects, but its heat (radiation) known here as radiant damage, still has effects. So it would still have an effect. Invisible doesn't mean ethereal. The invisible object or creature still has a solid form.

Yup! I had a Sunbeam-shooting Giant Owl in one fight.

Would characters with sunlight sensitivity have difficulty wielding this spell? Would be rather counterproductive to impose disadvantage on yourself while attempting to target an opponent. 

Quote from ADF >>

Would characters with sunlight sensitivity have difficulty wielding this spell? Would be rather counterproductive to impose disadvantage on yourself while attempting to target an opponent. 

This would definitely trigger their sunlight sensitivity but as long as they stick to forcing their targets to make saving throws, like with the beam created by this spell, then it shouldn't matter.

i assume its like a breath weapon and i would rule that its a straight line

Kamehameha

When creating a new line of radiance as an action does it do damage again with the new line?