[AD&D] Wargame style movement allowances for 1e hexcrawls

WARNING - this post contains hex-and-counter wargame terminology!

Partially inspired by the first part of this video, I decided to bite the bullet and codify hexcrawling movement value in my 1e AD&D campaign in terms of hex-and-counter board wargames. 

Wargames (I would prefer the term be reclaimed away from miniature games, but that's just me) are something I really enjoy and the counting of movement in hexes in terms of a unit's value is second nature to me, so this just makes sense. It does away with the B/X nightmare of terrain types causing 1/3 or 2/3 movement penalties and when you apply that across a multi-hex journey, and simply allows the party to move discretely from hex to hex, paying for terrain costs as they enter.

Though derived from AD&D materials, I see no reason this couldn't be used for any game with the 12/9/6 style movement.

So, here is the chart. I haven't yet tested this but I will do in my upcoming session this week. Read on if you care how I calculated the values.

So, first up, I'm not really a maths guy - I'm certainly no Delta. So there might be some wonkiness introduced by rounding or whatever the fuck. That being said, here's what I did.

 

1. Use the chart on pg 58 of the DMG to calculate the values in the Rugged and Very Rugged columns as fractions of the Normal values in each row. So for Light foot movement, Rugged is 2/3 of Normal movement, Very Rugged is 1/3 of Normal movement and so on.

2. Plug in and replace the PHB movement rates for foot. For mounted, round each Normal value to a preferred multiple of 6 to match my 6 mile hexes. It's only necessary for the Medium mounted and the Cart and Wagon. I've even got Gygax's blessing ("Some variation in the movement rate is justifiable") so shove it.  

Examples: Light Foot, using the PHB method for overland characters on foot, is 24, which is a multiple of 6. Medium Mounted is 40, so that became 42.

3. Divide our newly six'd Normal rates by six to get the Movement Allowance for this type of 'unit' in wargame terms. So Light Foot becomes 4, Medium Mounted is 7 etc. This is what the single counter's movement allowance would be if we were playing a wargame, and is the amount of clear hexes it could move through in one turn (day) all being well.

4. Use the fractional values of the Rugged and Very Rugged columns as calculated in Step 1 to figure out what their terrain cost is in terms of each Normal value we acquired in Steps 2 and 3. This is what it costs instead of 1 to enter this type of terrain.

Example: Given our assumed Normal values, a Draft horse has a movement allowance of 5 (that is, 30 miles/day, is five 6 mile hexes). The Rugged value on pg 58 of the DMG is 1/2 of the Normal value. Thus, it costs a Draft horse 2.5 movement points to move into a Rugged hex.
 
Further assumptions that I've made.

• Light, Average and Heavy rows for foot movement correspond to 12", 9" and 6" overland movement rates as usually determined by the PHB and whatever system you're using for movement allowance based on armour and the like.
  
• I treated the movement rates for the poor horsies given in the MM as top speeds to be used in combat, not journeys. As such I haven't applied the PHB movement rate for characters as mentioned above - I just stuck with the DMG chart values from pg 58.
• I fudged the rate for a Cart on Rugged terrain - if I did my maths right, it ended up with a movement cost of 1.666... so I just rounded to 1.5 for simplicity.
  
• The party will move at the speed of the slowest party member (although the nice thing about movement allowance here is that the 'stack' comprising the party can drop off 'units' if they need to and use up any remaining movement points to journey on)
• You'll need to determine how encumbrance affects all this given your chosen system. There's values in the DMG of course, but how they interact with the PHB system is...well...open to interpretation.
  
• You can always move one hex in a day, regardless of the cost. This is of course assuming there are no impassable barriers in the way. I've left the high Very Rugged costs for units in the chart despite the fact they all amount to 'only 1 hex movement'. This is to allow for spells or magic items that might increase your base movement (or the base movement of your mount).
• Roads? If it was a wargame you'd just treat as clear. Rivers? Sea? Don't wanna think about it just yet.
• Finally - even if the maths doesn't quite work out here (it's possible I may have slightly nerfed horse movement rate) it's consistent, which should be the most important thing.