CALEB!

Cool.

He said a wall of fire across the ship - but there were no maps or minis laid out. I wonder if Matt will allow Caleb to change his placement of the wall (a 20 ft. radius circle?) if he chooses after Liam sees the actual placement of everyone.

Caleb's dramatic cliff hanger has to be the most famous use of this spell in the history of D&D. Can't wait!

The rules here don't specify whether Wall of fire can set objects on fire. Can it?

No it can not, the default rules of magic are that magical fire damage does not set things on fire unless the spell says otherwise. 
I'm sorry I don't have a specific link for you to check out but I watched an interview with Jeremy Crawford a while back where he mentioned this (it's also somewhere in the books under the general magic rules).

Question: I can't find any information on the interaction of spells (or spell-like effects) ... What would be the effect of a White Dragon's breath weapon (or Cone of Cold) passing through a Wall of Fire?  Would the two diametrically opposed elements just cancel each other?  Would one spell overcome the other, dependent on each spell's casting level?  Would the damage rolled for the CoC be reduced by the WoF's rolled damage?   Would the CoC cause sections of the WoF to drop?  So many possibilities...!

If a wizard of the evocation school usea their ability on the tank to have them take no damage, would they still take no,damage if they end yheir turn on the side that deals damage?

Quote from Tyler_John >>

If a wizard of the evocation school usea their ability on the tank to have them take no damage, would they still take no,damage if they end yheir turn on the side that deals damage?

Sculpt Spell only allows to automatically succeed on saves. Since there’s no save involved with being near the wall after it’s erected, they’d still take damage at that point.

I looked this spell up right after the cliffhanger on c2e42 and I scroll down to the comments and people talking about Caleb’s epic moment. So so so so cool 

The rules are not super clear and I have had this debate with my DM, his ruling I have stuck with, but I am about to run a game myself and would like to know.

It says the dimensions of either the circle or the not circle, but can the not circle curve or snake along it's 60 feet? (same question for basically every wall spell).

Is this just a pre DM decision?

No. Spells do expressly and specifically only what they say. So unless a spell you read says it would do what you imagine in that hypothetical scenario, it doesn't.

This stands for fireballs and lightning bolts under water. Nothing changes because there is no clause in the spell for that. Fireball rolls full damage underwater, lightning bolt doesn't get extra area or extra damage.

Scenario that came up at our game last night.  Druid casts a ringed wall of fire and places it on top of two characters that take damage.  Would those characters be inside the ring and thus would be subject to the wall's damage when "entering" it again on their next turn if they wanted to escape or are the characters already in the wall of fire at the start of their turn and thus did not "enter" it on their turn and take no damage and could leave the ringed wall of fire without taking any more damage?

Quote from paigebrunswick >>

I looked this spell up right after the cliffhanger on c2e42 and I scroll down to the comments and people talking about Caleb’s epic moment. So so so so cool 

 Me too!!!! 🧙‍♂️😂😂😂

The rules are left intentionally vague for stream-lined effects. From a purely RAW standpoint, the effects of spells do only what they say they do and no more. Cone of cold and a White Dragon's breath do not mention that they extinguish flames in the area or cancel out spells, so RAW they would not interact with wall of fire. You can find an example of where this kind of interaction does exist by looking at the daylight spell. The spell mentions specifically that it cancels out spells of lower levels that create darkness effects. A similar example can be found on the darkness spell, which specifically says that it cancels out lower level light spells.

However, a DM may always rule otherwise. The rules bow to the DM, not the other way around.

Quote from Tyranthraxes >>

Scenario that came up at our game last night.  Druid casts a ringed wall of fire and places it on top of two characters that take damage.  Would those characters be inside the ring and thus would be subject to the wall's damage when "entering" it again on their next turn if they wanted to escape or are the characters already in the wall of fire at the start of their turn and thus did not "enter" it on their turn and take no damage and could leave the ringed wall of fire without taking any more damage?

 If the wall is cast on top of them, they take damage when it's created. But don't take more damage if they then move out of the wall (to the "cool" side) on their turn. They only take damage again if they leave & re-enter the wall, or stay in the wall at the end of their turn, or stay in range of the "hot" side at the end of their turn.

 So I have a big question for this spell. It can be cast "on a solid surface" within range. Does this mean you could cast it on a wall, and have it horizontally parallel to the ground?

In essence, this would allow the spell to become a 60-foot long and 20-foot wide line spell that lasts 1 minute, targeting (along a straight wall, more if it's curved) upwards of 48 creatures.

Yeah, except it’s explicitly stated in the underwater combat section of the basic rules that any creature fully submerged in water has resistance to fire damage.

Quote from Adeptus >>

Quote from Tyranthraxes >>

Scenario that came up at our game last night.  Druid casts a ringed wall of fire and places it on top of two characters that take damage.  Would those characters be inside the ring and thus would be subject to the wall's damage when "entering" it again on their next turn if they wanted to escape or are the characters already in the wall of fire at the start of their turn and thus did not "enter" it on their turn and take no damage and could leave the ringed wall of fire without taking any more damage?

 If the wall is cast on top of them, they take damage when it's created. But don't take more damage if they then move out of the wall (to the "cool" side) on their turn. They only take damage again if they leave & re-enter the wall, or stay in the wall at the end of their turn, or stay in range of the "hot" side at the end of their turn.

 Thanks, that makes sense!

Casting word is:

Transium Ignitus

I want to cast a circle wall around a group of enemies and roast them alive