(considers Gary's post above)
Rats. Another evil plan by my characters to take over the D&D worlds foiled.

I don't get to wipe out $60 spent by the DM and 10 to 20 hours (or more) of preparation on his part with a single spell. Nuts. It's totally unfair. It's unfair, I tell you! Unfair!
Anyways ...
The tactic I suggested (using the Rock to Mud) caused me to ask: what could I do, if my characters had a castle, to protect against it (assuming a DM used such tactics as the Rock to Mud tactic.)
The first thought that came to mind was Wall of Force.
So ...
Just how powerful is Wall of Force? How much damage will it take before it collapses? I have had to make a lot of arbitrary rulings on this, since the spell is not invincible but it is very powerful.
Now, I'm curious on your take.
For example, let's say a Wall of Force cast by a 10th level wizard has 1,000 hit points? An 11th level wizard would create a Wall of Force with 1,210 hit points? A 12th level wizard would create a Wall of Force with 1,440 hit points?
- Perhaps a 6 dice fireball removes 6 points, and a 30 hit dice fireball 30 points from the Wall (plus the level of the spell in points, plus the level of the caster, in points) ?
- Spells and items that fire other spells that inflict dice of damage (Cone of Cold, Lightning Bolt, etc.) would inflict 1 hit point per hit dice of damage on the Wall (plus the level of the spell and the level of the caster, or the level required to create the item plus the level of it's spell plus the level of it's user) ?
- Other types of spells (enchantment, illusion, wild magic, etc.) successfully deflected by the Wall cause it to sustain hit points of damage equal to the level of the spell (plus the level of the spell and the level of the caster) ?
- Innate spell-like attacks cause 1 point of damage to the Wall per spell level equivalent, plus the a number of points of damage equal to the hit dice of the monster?
- A weapon hit, does no damage, except for it's magical bonus, counted in points of damage (a + 3 sword does 3 points.) ?
- A stick of dynamite would do 1 point per hit dice of blast damage? (So, your typical stick of dynamite would do 6 points of damage.)
- A firearm would do 1 point per hit dice of damage caused (including the area effect attacks of weapons like gatling guns, mini-guns, etc.) ?
- An energy weapon attack (such as a lightsabre, plasma cannon, phaser, whatever) would do 1 point of damage per hit dice of damage caused?
- Disintegration attacks would down the Wall, without harming what was behind it?
- The Wall would lose, say, 1 point per ton of impact (that is, a 100 ton locomotive running into it would cause 100 hit points of damage. A 100 ton dragon flying into it would do likewise) ?
- The Wall could hold up 1 ton of weight per hit point? Doubling the weight beyond that would inflict 1 hit point per round on the Wall? Doubling the weight beyond that would inflict 10 hit points per round? Doubling the weight beyond that would inflict 100 hit points per round on the Wall? Any weight beyond that would cause the Wall to instantly collapse?
What is your take?
I've been wanting to ask THIS question for many, many years!
Edena_of_Neith