Extent

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Latest revision as of 02:39, 9 October 2010

The Extent codes are an attempt to systematically designate area sizes, primarily from a social perspective, and covering a wide scale, from a single Village and all the way up to an entire Galaxy.

About the Extent scale

The scale is mostly used for social traits, such as Perks, and a few social effects such as the magical effects of Rune-Carved magic items (Runestones and Spite-Statues), because the Extent scale tries to take into account population density, instead of looking solely at physical area.

The Extent scale

Notes on Extent Codes

Extents are a peculiar combination of physical area and population size, and as two areas with the same Extent code can easily be of very different size, one perhaps 20 or 30 times as large as the other, the Extent Code system is best used only for ore or less sociological phenomena, such as Reputations and Popularities, and the Area Knowledge skills.

Nation sizes in particular are time period dependent. In a modern era setting (2010 or so), Charlemag'ens Holy Roman Empire, consisting of what is now France, Germany and Italy, should not actually rate as a Large Nation, but only as a Medium Nation. A Large Nation is something like the USA or the European Union. Also note that Australia is too small to qualify as a Continent, regardless of time period (Europe is small in area, but densely populated, and rather important in any time period up until the present day, and will remain important at least for the next few decades).

Extents are somewhat fuzzy, and cannot avoid being so.

A Megapolis is a huge city. A modern day example would be New York. London has been a megapolis since some point in the 18th or 19th century. Rome was a megapolis during the Roman age, and the subsequent middle age and renaissance due to its importance as the seat of the highest priest of the Catholic religion, but should almost certainly not qualify as a Megapolis in a present day campaign.

Alternative Extents

Combination Extents should always be allowed. If a player wants to create a character who is Popular or Famous in Eastern Europe and western Asia, then it is perfectly legitimate to define Eastern Europe and western Asia as being a Large Nation. Also, character should usually be a allowed to include minor areas as belonging to larger Extents, when that makes sense, for instance on Ärth Sláine of Ulster is Popular in Ireland, but he spends a lot of time on the Island of Skya, so even though Skya is part of Britain, not Ireland, the GM of any such campaign should allow Skya to be included in the definition of the Small Nation of Ireland, for the purpose of Släine's Popularities and Reputations (but not Area Knowledge skills; these are easy to buy seperately). And please note that the Island if Skya is small relative to Ireland. Ireland is a Small Nation (Ex2), and the Island of Skya is a Region (Ex4).

Likewise, one could have an Extent that is a Gas Giant and its moon and any facilities orbiting the Giant or its moons, such as in Iain M. Banks science fiction novel "The Algebraist" (from the perspective of the so-caleld Dwellers". Given how much real estate there is in Jupiter and its moons (even just the four largest ones), that should count as ExC9, same as the Inner Solar System. It's a bit on the small side for that, but on the other hand it's much too large to count as ExC8.5, at least after decades of colonization and exploitation.

On Galaxies

Galaxies are huge. Friggin' huge. It may seem superflous to sub-divide a Galaxy into so many Extent levels, but if one thinks about it, there are something like 200 billion solar systems in a typical galaxy (such as the Milky Way Galaxy), which is a lot.

For the purpose of Slices, envision the Galaxy as a hexagon divided into seven parts. In the center is the core, plagued by a flux radiation so intense that neither living beings nor robots can even dream of visiting it, unless aided by very advanced futuristic technology. The "usable" portion of the Galaxy is then the six "Slices" along the edge, each comprising a significant portion of the volume of the Galaxy (and a significant portion if the Galaxy is viewed from above as a 2-dimensional place). Sol, the sun of Planet Earth, is very roughly half-way (25'000 Light Years) between the exact center of the Milky Way Galaxy and its "edge" (although note that there is no real edge; only a point where the density if suns begins to drop off much more drastically), and so the diamter of the Core is obviously much less than 50'000 LY.

The Core is small in volume, but high in solar density (in terms of solar systems per cubic LY).

Galactic Sectors and larger Extents

If one posits that each Extent step, above Entire Solar System (ExC10), contains 20 times as many solar systems, then one reaches only 64 million solar systems at ExC16 (Galaxy), so obviously a much more drastic multiplication factor is needed (also keeping in mind that what one really wants to "reach" is 20 billion systems at Ex15, not 200 billion systems at ExC16).

If one posits that each Extent step from ExC10 to ExC15 contains 100 times as many solar systems, then at Ex15 one reaches 10 billion systems at ExC15, which is nearly correct. So a little more than 100 times as many systems per ExC steps. A factor of 115, ugly as it is, actually does the job (assuming 4/10 of the systems are in the Core).

One can thus visualize each Galactic sub-Sector as being almost 5 solar systems in each dimension. 5 solar systems high, 5 solar systems wide, and then perhaps 4 or 5 solar systems deep.

Likewise each Galactic Sector is 5 sub-Sectors in each dimension, although at high Extent Codes one must start dealing with the fact that the Milky Way Galaxy, as well as many other Galaxies, are somewhat flat. At sufficiently high Extent Codes, it becomes justified to use a two-dimensional map. Certainly when talking about Galactic Slices (which are much flatter than the Core), but perhaps also Galactic Regions.

Keep in mind, for the vast majority of campaigns, this won't matter. But it's good to have some infrastructure in place for those rare campaigns where it does.

2D Galaxies

If one uses a two-dimensional map, i.e. completely and explicitly ignoring the third dimension, then things become much simpler (such as in most, if not all, versions of the Traveller RPG setting), although one shouild probably also then pretend that a Galaxy has fewer solar systems in it than they have in our fully three-dimensional world. It may even be possible, in a 2D Galaxy, to drop one of the Extent Codes, so that Galaxy is ExC15. The most obvious Extent to drop is the Slices.

Say that the scale stops at ExC15, Galaxy. Let's drop the number of systems from 200 billion to 10 billion. Half of those are in the Core, leaving 5 billion that must be sub-divided and sub-divided again, and then sub-divided some more, so that things can be defined with some precision (e.g. keeping track of the criminal progress of a certain felinoid who desires to be "wanted" in the entire Galaxy).

We have five steps, from ExC11 to ExC15, so the multiplication factor must be around 87 per step. Each sub-Sector contains 87 systems, each Sector contains 87 sub-Sectors (thus 87^2 systems), and so forth. This means each step is roughly 9 x 10 times as large as the previous. A sub-Sector is 9 systems on one side, 10 on the other. A Sector is 10 sectors on one side, 9 on the other side.

The Core still exists, but since it cannot be visited, even by heavily shielded probes, it can be ignored, except as an obstable that one must travel around (and in which case it is easier to obstruct such travelling-around because setting up strategic barriers is almost infinitely easier in 2D space than in 3D space. A malignant space empire (or a huge fleet of von Neumann machines) can easily control a narrow slice of a 2D Galaxy, with military presence, so that people wanting to get to the other side have to travel the long way around the Core to get there).

What you need to memorize/internalize

For a typical campaign:

• Village
• Town
• City
• Megapolis/Region
• Small Nation
• Medium Nation
• Large Nation
• Continent.

Village, Town and City all have corresponding informal non-Urban Extents (Community, Parish and County, with Region being more formal) but these don't usually need to be memorized as terms; just remember that they exist (i.e. ExC2 doesn't have to be a City).