I've been playing D&D for a long time but I've never encountered this situation until now. If a party has a wizard and a sorceress who both know Wall of Fire, can they cast it in the same place? Say most of the enemies are standing in a big conga line and it's clearly one of the best spells to take them out. The mages happen to come one after the other in the turn order.
The description of Wall of Fire says:
When the wall appears, each creature within its area must make a Dexterity saving throw. On a failed save, a creature takes 5d8 fire damage, or half as much damage on a successful save.
One side of the wall, selected by you when you cast this spell, deals 5d8 fire damage to each creature that ends its turn within 10 feet of that side or inside the wall. A creature takes the same damage when it enters the wall for the first time on a turn or ends its turn there. The other side of the wall deals no damage.
Do the enemies standing in the area of effect take damage from each of the spells when they are cast? If they end their turn in the double fire wall, do they take 5d8 damage from each caster? For instant spells like Acid Splash it makes sense to me that the damage is applied with each cast, even if it is the same type. But if it's a continuous area of effect like Cloud of Daggers (PHB, p. 222), do the damages stack?