Rules of the Game
Going Metric (Part One)
By Skip Williams

So, you enjoy the D&D game, but you hail from a place where the metric system rules minor little things such as weights and measures. Well, you could buckle down and learn the good old English system. After all, it was developed in the Middle Ages, and it reflects a medieval approach to numbers. The system lends itself to division by halves, thirds, and quarters, which can be pretty handy if you're an illiterate peasant who lives in a cash-poor society where most personal transactions are accomplished through barter. So, using the English system will give you a more authentic medieval setting.

Okay, so you're not so dedicated to an authentic medieval setting. You grew up thinking metric and you'd like to have a better idea of what the game's measurements actually represent. The table below shows some common English units and their metric conversion factors.

Game Measurement Multiply By To Get
Length
Inches 25.4 Millimeters
Inches 2.54 Centimeters
Feet 30.5 Centimeters
Feet 0.305 Meters
Yards 0.914 Meters
Miles 1.61 Kilometers
Leagues[1] 4.83 Kilometers
Area
Square inches 6.45 Square centimeters
Square feet 0.093 Square meters
Square yards 0.836 Square meters
Square miles 2.56 Square kilometers
Acres 0.405 Hectares
Volume
Fluid ounces 29.6 Milliliters
Pints[2] 0.473 Liters
Quarts[2] 0.946 Liters
Gallons[2] 3.79 Liters
Cubic feet 28,000 Cubic centimeters
Cubic feet 0.028 Cubic meters
Weight[3]
Ounces 28.3 Grams
Pounds[3] 0.454 Kilograms
Tons[3] 0.907 Metric tons

1. One league equals 3 miles
2. US measure
3. Short ton (2,000 pounds)

Converting Tactical Distances

The basic unit of distance for all tactical movement and combat in the D&D game is 5 feet, which is the size of one square. Also, all ranges are given in numbers evenly divisible by 5. The conversion table shows that 5 feet is about 1.525 meters (5x0.305=1.525). The number 1.525 isn't a very practical one for gaming, so let's say that 5 feet equals 2 meters for game purposes. Why 2 meters? First, an even, whole number is more convenient to use than something that's closer to the mark, such as 1.5 meters. Also, other d20 games that were designed from the beginning using metric measurements, such as the Star Wars game, already use 2-meter squares.

It's important to make all our distances conform to this number rather than trying to convert them directly. For example, a character with a speed of 30 (feet) has a speed of 12 (meters) in the metric game (not a speed of 9.15 meters). In either case, the character travels 6 squares in one move action.

The table below shows common tactical speeds and their metric conversions:

Speed Table (English Units)
Tactical Speed*
Base Speed 100 90 80 70 60 50 40 30 20 15 10 5
(squares) 20 18 16 14 12 10 8 6 4 3 2 1
Encumbered 70 65 60 50 40 35 30 20 15 10 5 5
(squares) 14 13 12 10 8 7 6 5 3 2 1 1
One Minute (Local)*
Current Speed** 100 90 80 70 60 50 40 30 20 15 10 5
Walk 1,000 900 800 700 600 500 400 300 200 150 100 50
Hustle 2,000 1,800 1,600 1,400 1,200 1,000 800 600 400 300 200 100
Run (x3) 3,000 2,700 2,400 2,100 1,800 1,500 1,200 900 600 450 300 150
Run (x4) 4,000 3,600 3,200 2,800 2,400 2,000 1,600 1,200 800 600 400 200
One Hour (Overland)***
Current Speed** 100 90 80 70 60 50 40 30 20 15 10 5
Walk 10 9 8 7 6 5 4 3 2 1.5 1 0.5
Hustle 20 18 16 14 12 10 8 6 4 3 2 1
One Day (Overland)***
Current Speed* 100 90 80 70 60 50 40 30 20 15 10 5
Walk 80 72 64 56 48 40 32 24 16 12 8 4
*Tactical and local speeds are in feet.
**Use normal or encumbered speed, whichever applies to the creature.
***Overland movement is measured in miles.


Speed Table -- English to (Metric Units)
Speed (feet) 100 90 80 70 60 50 40 30 20 15 10 5
Speed (meters) 40 36 32 28 24 20 16 12 8 6 4 2
Speed (squares) 20 18 16 14 12 10 8 6 4 3 2 1
Speed Table (Metric Units)
Tactical Speed*
Base Speed 40 36 32 28 24 20 16 12 8 6 4 2
(squares) 20 18 16 14 12 10 8 6 4 3 2 1
Encumbered 28 26 24 20 16 14 12 10 6 4 2 2
(squares) 14 13 12 10 8 7 6 5 3 2 1 1
One Minute (Local)*
Current Speed** 40 36 32 28 24 20 16 12 8 6 4 2
Walk 400 360 320 280 240 200 160 120 80 60 40 20
Hustle 800 720 640 560 480 400 320 240 160 120 80 40
Run (x3) 1,200 1,080 960 840 720 600 480 360 240 180 120 60
Run (x4) 1,600 1,440 1,280 1,120 960 800 640 480 320 240 160 80
One Hour (Overland)***
Current Speed** 40 36 32 28 24 20 16 12 8 6 4 2
Walk 24 21.6 19.2 16.8 14.4 12 9.6 7.2 4.8 3.6 2.4 1.2
Hustle 48 43.2 38.4 33.6 28.8 24 19.2 14.4 9.6 7.2 4.8 2.4
One Day (Overland)***
Current Speed* 40 36 32 28 24 20 16 12 8 6 4 2
Walk 192 172.8 153.6 134.4 115.2 96 76.8 57.6 38.4 28.8 19.2 9.6
*Tactical and local speeds are in meters.
**Use base or encumbered speed, as applicable.
***Overland speeds are in kilometers.

Coming in Part Two of Going Metric

Skip covers thrown and projectile weapon ranges, spell ranges, and spell areas.

About the Author

Skip Williams keeps busy with freelance projects for several different game companies and has been the Sage of Dragon Magazine since 1986. Skip is a co-designer of the D&D 3rd Edition game and the chief architect of the Monster Manual. When not devising swift and cruel deaths for player characters, Skip putters in his kitchen or garden (his borscht gets rave reviews).


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