Template:Size Modifier

Size Modifier rates a person or object's most significant dimension: length, width, or height. It is a modifier to rolls to hit you in combat and to Vision rolls made to spot you. Thus, it is a bonus for large creatures, a penalty for small ones. Although large creatures are easier targets, a positive SM qualifies them to buy ST and HP more cheaply by taking the "Size" limitation.

Most humans – and humanoids, robots, etc. that can pass for human – have SM 0, and can ignore this rule. Nonhumans use the SM on their racial template. However, your SM may deviate from racial average if you are not full-grown, or if you are a genetic dwarf or giant.

When creating a creature that is larger or smaller than a human, find its SM by looking up its longest dimension – height for upright creatures such as giants, length for horizontal creatures such as cats and dragons, diameter for blobs – on the Size Modifier Table.

If a creature's longest dimension falls between two entries on the table, base its SM on the higher value. Box-, sphere-, or blob-shaped characters add +2 to SM; elongated boxes, like most ground vehicles, add +1.

It is neither an advantage nor a disadvantage to have a nonzero SM – the benefits and drawbacks tend to cancel out. The exceptions are genetic dwarfism and gigantism, as these conditions affect bodily proportions (notably relative arm and leg length) and have social ramifications (you stand out in a crowd).