Can I direct a Flaming Sphere from behind Wall of Force?

[yeti1069]

If I already have a Flaming Sphere up, and cast a Wall of Force, can I direct its movement? I’m not targeting anything and not creating an effect. Can I have it roll in a general direction?

[Whisperer in Darkness]

that depends on the size of the Wall of Force and the circumstances of the situation as it deals with Line of Effect(LoE) and spell range. Losing LoE generally cuts off a caster from a spell effect. I'd have to look up that last statement in RAW to prove it but I'm pretty sure it is correct and may involve several statements in RAW

If a wizard casts a spell such as Flaming Sphere and then is put in a glass walled cube he loses LoE to the spell effect even though it is visible{Line of Sight-LoS}(it is not a gaze effect).
There other physical problem is spell range (falling into a pit and exceeding the maximum range of the spell).
Thus a Wall of Force may not block LoE if a flexible LoE can be drawn around the barrier connecting the caster and spell effect and the LoE is less than the range of the spell. A Wall spell is most effective when the barrier seals away the offending party cutting all LoE and LoS.

The game also quantizes space into imaginary 5ft cubes called squares. This can affect things at times as a caster need only target a square to place an effect within it. Most walls don't meet the squares on maps so there's some wiggle room as circumstances dictate.

[Ravingdork]

I don't see why not.

[Pizza Lord]

I see nothing in Line of Effect or in redirecting or concentrating on a spell that indicates that you need Line of Effect to do either. In the case of your flaming sphere or even a spiritual weapon being on the other side of a wall of force, it works fine. You couldn't cast a spell across it or have its origin be in a location or target area you didn't have LoE to, but once there, as in your example, you could use it fine. It wouldn't be able to come through the wall, in the case of a spiritual weapon that wasn't being directed or that left the spell range or you lost sight of. It would try but would be blocked.

You could direct a spiritual weapon to a new target, roll a flaming sphere around (or even have it jump over the wall), direct your dancing lights (no concentration needed), or control a dominated target via the telepathic link created by the spell when you established it. You just couldn't cast the spells or have their point of origins on a target to which you didn't have LoE when they were generated.

You could also concentrate to maintain or move illusions around (in their designated areas). In such a case, assuming you had already established the designated area (typically an amount 10-foot cubic area, in the case of most ... image line of spells), then you can have an illusion seem to be passing through a solid object, like a glass wall or clear ice sheet. This may or may not apply to wall of force though, depending on how you read its wording that it stops spells from passing it, which may be above and beyond or separate from any rulings on LoE (which it has been stated it blocks in Dev comments, if not in the spell itself). If the LoE blocking effect is in place when you cast the spell, any attempted placement of designated space beyond the barrier would not manifest (nor any part of the illusory object or creature extending that far).

[Falkyron]

You need line of sight for those spells, but it says nothing about line of effect. A wall of force is invisible. While it wouldn't work with opaque barriers, nothing seems to prevent you from directing your flaming sphere from behind a transparent barrier.

yeti1069 wrote:

I’m not targeting anything and not creating an effect. Can I have it roll in a general direction?

Flaming Sphere wrote:

A burning globe of fire rolls in whichever direction you point and burns those it strikes. It moves 30 feet per round. As part of this movement, it can ascend or jump up to 30 feet to strike a target...

...The sphere moves as long as you actively direct it (a move action for you); otherwise, it merely stays at rest and burns.

This implies that it follows where you intend for it to go rather cleverly. It probably can even move in serpentine patterns if you want to be silly.

Flaming Sphere wrote:

If it enters a space with a creature, it stops moving for the round...

If you take a move action to direct it and it doesn't bump into somebody, there's no reason you can't just do tricks with the thing and hurt nobody. You can make it run circles around somebody and never strike them if you want.

Note though that is has a hard movement cap of 30 feet per round, not 30 feet per move action.