How do you attack a creature behind a Wall of Sand?

Question

The spell Wall of Sand reads:

Creatures with reach can attempt to attack through the wall, but targets have total concealment and total cover, and the attacker must have a general idea where the target is located. (Spell Compendium, p. 235)

But the section on total cover says (emphasis mine):

Total Cover: If you don’t have line of effect to your target (for instance, if he is completely behind a high wall), he is considered to have total cover from you. You can’t make an attack against a target that has total cover. (PHB p. 152)

How is that supposed to work?

Answer 1

You can't attack through that wall of sand

This reader suspects that it's simply a mistake for the the final version of the 4th-level Sor/Wiz spell wall of sand [conj] (Spell Compendium (Dec. 2005; Apr. 2013) 237) to imply that most creatures can make attacks through the total cover the spell's effect provides. (Like this answer suggests, the rules as written may permit some exceptional creatures to make attacks through this wall of sand spell's effect, but that's not nearly the volume of creatures the spell's description implies!)

This reader suspects the idea of attacking through the wall of sand spell's effect is an accidental holdover from the the two markedly different earlier versions of the spell through which anyone could make attacks… with sufficient effort.

For comparison, the original version of the 4th-level Sor/Wiz spell wall of sand [conj] (Player's Guide to Faerûn (Mar. 2004) 118) says, in part, that

It is possible to attack a character inside or on the far side of the wall of sand with a melee weapon, provided that the following criteria are met. First, the attacker must have a general idea where the target is within the wall (that is, she must have seen her target enter the wall recently). Secondly, the target must be no deeper into the wall than the reach of the attacker’s weapon (or, in the case of creatures on the far side of the wall, the wall itself must not be deeper than the attacker’s reach). Even then, the target benefits from cover and total concealment.

Similarly, the second version of the 4th-level Sor/Wiz spell wall of sand [conj] (Sandstorm (Mar. 2005) 127) says, in part, that

No form of physical attack can harm a wall of sand directly, but each 10-foot section has 2 hit points per inch of thickness for determining whether an attack passes through it. The wall reduces damage dealt by attacks that pass through it. It essentially absorbs damage, so attacks must deal more damage than the wall has hit points to have any effect on a target on the other side of the wall of sand. Breaches in the wall close immediately after the attack that made them passes through. The sand blocks line of effect for any fire spell. Creatures on the opposite side of the wall from an attack’s origin have total concealment against that attack.

Many wall spells that originally appeared in other publications were substantially changed—if not outright rewritten—by the Spell Compendium (cf. the spell wall of water). This spell is no exception.

Answer 2

You can attack, but...

...you must have an additional form of sensory input which bypasses the wall and allows you to either pinpoint the square, or to actually perceive accurately where your target is in relationship to you.

This is because the comment on total concealment and cover is dependent upon the fact that the Wall of Sand is assumed to be between your square and your target's square.

For example, if you had an X-ray vision effect going on, you could potentially see through the wall of sand.

Other options include:

• Clairavoyance
• Certain Detect effects could negate the total cover
• Some of the Eye powers and spells could likewise negate total cover
• Touchsight also is frequently considered to negate certain forms of concealment, and might negate the total cover depending on where exactly your square, your target's square, and what squares are occupied by the Wall of Sand
• Tremor sense
• Large scale area of effect attacks
• Any other form of unusual vision, sensory apparatus, or pinpointing technique: eye stalks, blindsight, seeing through another's eyes, etc.

Please keep in mind that some of these effects require Concentration, which potentially can affect what types of attacks you are able to perform in the same round.

Also note that the Spell Compendium version denotes the wall to be 10 feet thick, whereas the other two versions of this spell (Sandstorm and PGtF) are 1" per level and 5' square per level respectively. Given the Spell Compendium version, only the Touchsight and X-ray effects could potentially locate a target inside the wall.

Once you have dealt with these challenges, you can attack through the Wall of Sand, though this one notes that it may be simpler and less of an action tax to just move through or around it.

Answer 3

The description of Wall of Sand really contradicts itself rules-as-written wise.

Still I believe spell author's intent is simple enough: it provides total cover from anything other than melee attacks. Your first quote may still make sense as a single sentense if you, for example, have blindsight and tremorsense. With tremorsense (turns around corners) you can pinpoint your target. With blindsight you can ignore total consealment granted by the wall. But thanks to the fact the wall provides total cover, your blindsight is blocked. So you can attack in melee, you know the square, but suffer a miss chance.

You may also rule it still provides cover against melee attacks considering it's description from Player's Guide to Faerun, but such a ruling would be no more than a reasonable homerule if Spell Compendium (last reprinting of the spell) is in play.