One of my players is asking if he can use Wall of Fire to block off the line of sight of enemy archers. The spell description says the wall is "opaque", so this seems like a valid thing to try.

However, because this opaque wall would make both sides unseen from each other, the advantage and disadvantage would cancel out, and it would provide no immediate tactical benefit.

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> When you attack a target that you can’t see, you have disadvantage on the attack roll.
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> When a creature can’t see you, you have advantage on attack rolls against it. (PHB p. 193-4)
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In the interest of trying to see if he can get any tactical benefits out of this - **if he blocked the line of sight of the enemy archers in a group but not that group's melee fighters, would he/others be able to take the Hide action from the archers even if the melee fighters could still see him?**

If he can Hide in this way, that would mean the archers would no longer be able to know his precise position and would need to guess his square before making an attack.