Building the Wall

Being short of ideas myself, I was scrapping around on Twitter today for ideas on what to write about. @rtassicker suggested I write about Walls, and if I can figure out how they're costed.

So here goes.

I guess the first reference point are the original walls. Here are the main ones:

Key Alpha Walls

Wall of Wood - G - 0/3
Wall of Ice - 2G - 0/7
Wall of Air - 1UU - 1/5
Wall of Water - 1UU - Waterbreathing - 0/5
Wall of Bone - 2B - B to regenerate - 1/4
Wall of Stone - 1RR - 0/8
Wall of Fire - 1RR - R Firebreathing - 0/5
Living Wall - 4 - 1: Regenerate - 0/6

Although the costing of these Walls feels a bit all over the place, the first two give a good example of comparative costing.

Wall of Wood - G - 0/3
Wall of Ice - 2G - 0/7 (Should a Wall of Ice be blue?)

Wall of Ice indicates that +0/+2 toughness could be added for each additional cost in colourless mana. Another interesting comparison is Wall of Stone and Wall of Fire. Wall of Fire gives up 3 toughness and gains firebreathing. However, the difference between Wall of Air and Wall of Water is far more subtle, giving up a single point of power for 'Water'breathing. This would mean that 1 point of power is equal to a special ability in the world of Walls.

Since Ice Age, there is another mana acceleration wall strictly better than Wall of Wood:

Tinder Wall - G - mana ability - 0/3

With Wall of Wood, Wall of Ice and Tinder Wall in mind, we can find two notable 1G Walls:

Wall of Blossoms - 1G - When ETB, draw a card - 0/4
Wall of Roots - 1G - mana ability - 0/5

Wall of Blossoms sacrifices a single toughness for a card - not a bad deal. Wall of Roots allows itself to shrink in order to mana accelerate, rather than outright sacrifice itself. Wall of Blossoms is from the Stronghold cycle of walls:

Stronghold Walls

Wall of Blossoms - 1G - When ETB, draw a card - 0/4
Wall of Razors - 1R - First Strike - 4/1
Wall of Sorrows - 1B - Deals dmg received to opponent - 0/4
Wall of Tears - 1U - Unsummon blocked creature - 0/4
Wall of Essence - 1W - Lifegain - 0/4
Shifting Wall - X - X +1/+1 counters - 0/0

This cycle establishes a 1X cost as a 0/4 wall with an on-flavour ability. If a vanilla 2CC wall should be 0/5 then it seems adding an ability meant the sacrifice of a single toughness during Stronghold.

There is also an established theme for 3CC cost walls:

Wall of Granite - 2R - 0/7 (Portal)
Glacial Wall - 2U - 0/7 (7th Edition)
Wall of Ice - 2G - 0/7 (Alpha)

All 0/7 vanilla walls, each following the +2 tougness rule/colourless mana. So lets take a look at some more 'Modern' Walls in comparison.

Modern Walls

Steel Wall - 1 - 0/4 (Mirrodin)
Wall of Reverence - 3W - Flying, lifegain ability - 1/6 (Conflux)
Wall of Denial - 1UW - Flying Shroud - 0/8 (Alara Reborn)
Wall of Frost - 1UU - Blocked creature 'sleeps' for a turn - 0/7 (M10)
Wall of Faith - 3W - W gain +0/+1 - 0/5

M10 saw fit to reprint two walls:

Wall of Bone - 2B - B to regenerate - 1/4
Wall of Fire - 1RR - R Firebreathing - 0/5

If you consider the +1 power for -2 toughness, then add regeneration, then Wall of Bone is slightly undercosted still. Wall of Fire seems appropriately costed. However, they are both probably included in the set as good Limited fodder and nother more.

My analysis leads me to believe the base costing of vanilla Walls is as follows:

X - 0/3
1X - 0/5
2X - 0/7
4X - 0/9

Two further rules apply:

1. A wall can sacrifice two points of toughness for a point of power.
2. A wall can sacrifice a point of toughness for an abilities.
3. A wall can 'buy' an ability by sacrificing a colourless mana cost for a colored mana cost.

This makes the following walls viable:

X - 1/1
1X - 1/3
1X - 2/1
2X - 1/5
2X - 2/3
2X - 3/1

or

X - 0/2 - Something
1X - 0/4 - Something
2X - 0/6 - Something
3X - 0/8 - Something

This makes sense for the calculation for Wall of Frost:

* Base 2U wall - 0/7
* Buying an ability for colored mana - 0/7, 'sleep' ability

And the calculation for Wall of Reverence:

* Base 4W wall - 0/9
* Sacrifice two toughness for a point of power - 1/7
* Sacrifice a point of toughness for abilities - 1/6

But the calculation for Wall of Denial shows it to be slightly undercosted:

* Base 2W Wall - 0/7
* Buying abilities with colored mana swap - 0/7, Flying, Shroud

I would hazard a guess that the extra point of tougness is for the dual-colour mana required.

The rules seem to go out fuzzy around 1CC walls, but otherwise seems to hold up okay. At any rate, it should give you a rough guide to what walls you may see in the future.