17th level Wizard casts Prismatic Wall in sphere form, centered on victim. Wizard makes his ally Fighter immune to the Wall, (along with himself.)
Eldritch Knight fighter that previously hasted self then grapples victim and uses his movement to drag the enemy through the sphere. Takes 10 ft of movement to move them 5 ft out of the sphere.
Then fighter turns around and drags victim back into the sphere.
Repeat until dead.
Granted this takes a high level wizard and strong fighter.
But is this combo legal? Honestly, it seems almost certain death with little the victim can do to escape.
When a creature attempts to reach into or pass through the wall, it does so one layer at a time through all the wall’s layers. As it passes or reaches through each layer, the creature must make a Dexterity saving throw or be affected by that layer’s properties as described below.
If we want to be sticklers about it, it technically references "a creature that attempts", which implies agency. This could be used to argue that forced movement wouldn't trigger the wall, however that could lead to weird loopholes.
I'd rule that the layers of the wall are either bypassed, by applying the fighters immunity to the entangled mass, or when the layer triggers for the enemy, the fighter is caught in the effect due to physical contact. Shoving would be less clear, but unidirectional.
17th level Wizard casts Prismatic Wall in sphere form, centered on victim. Wizard makes his ally Fighter immune to the Wall, (along with himself.)
Eldritch Knight fighter that previously hasted self then grapples victim and uses his movement to drag the enemy through the sphere. Takes 10 ft of movement to move them 5 ft out of the sphere.
Then fighter turns around and drags victim back into the sphere.
Repeat until dead.
Granted this takes a high level wizard and strong fighter.
But is this combo legal? Honestly, it seems almost certain death with little the victim can do to escape.
If we want to be sticklers about it, it technically references "a creature that attempts", which implies agency. This could be used to argue that forced movement wouldn't trigger the wall, however that could lead to weird loopholes.
I'd rule that the layers of the wall are either bypassed, by applying the fighters immunity to the entangled mass, or when the layer triggers for the enemy, the fighter is caught in the effect due to physical contact. Shoving would be less clear, but unidirectional.
Weaponizing prismatic wall for multiple forced pass throughs certainly isn't RAI.
I think the key word is "attempts". Grappled creatures are not able to move, let alone attempt.