Scale vs. Size
Scale and Size, are closely related terms that are often confused with each other in regards to playing or discussing Mobile Frame Zero. If you are six foot tall, and someone scans you and prints out a statuette of the scan at two feet tall, then that statuette is a one third scale model of you. If they print out the scan at one foot tall, then it would be a one sixth scale model of you. The scale of the statuette is one sixth because it would take six of them to equal the height of the source material, in this case you. The “size” of the one sixth scale model is one foot, or twelve inches.
Within the Mobile Frame Zero community it has become agreed upon through common usage that the “scale” of a game played will not be given a number based on fractional relationships to real world objects but a number based on how many Lego plates it takes to equal six feet. When I first started talking about scale, I found the average height of an adult man is five feet and ten inches. I figured with the addition of combat boots and a helmet the “average” man would then be an even six foot tall.
The Rule book has a background universe in which ground combat is based on a “seven plate scale” standard, but the rules and mechanics are not tied to any one scale. As long as the game pieces fit within the “suggestion box” and the ruler is the same length, then the game plays the same, no matter what the scale of the terrain. My preferred scale for game play is five plate scale, although I do have three different forces in seven plate scale.
If you have the space for bigger games you can increase the size of the “suggestion box” and the length of the ruler. The game will play the same. It will just require more space to play. The same is true in the other direction. If you have less space to play, you can reduce the size of the “suggestion box” and shorten up the ruler.