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Old 05-20-2016, 03:08 PM   #1
johndallman
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Default [Basic] Skill of the week: Navigation

Navigation is the IQ/A TL skill of finding out where you are and plotting a course to get somewhere else. Specialisation in a kind of environment is required: (Air), (Land) and (Sea) default to each other at -2; (Space) and (Hyperspace) default to each other at -5, with no defaults between the two groups. If there are several forms of faster-than-light travel in a game, they may have different forms of (Hyperspace), aka Astrogation. The skill covers careful observation of your surroundings and the use of instruments, of any degree of sophistication appropriate to the TL. Cartography and Mathematics (Surveying) have defaults to Navigation, and Shiphandling has a prerequisite of an appropriate Navigation specialty.

The GURPS history of the skill is somewhat complicated: it appeared at 1e, assuming navigation by the stars, and working on land or sea, but not considering air or space. 3e added Astrogation, and Special Ops added Orienteering, which used maps, landmarks, and compass or GPS, but not the stars. G:WWII allowed Navigation to work in the air, but kept Orienteering, and 4e combined and generalised all these skills. However, historical compatibility has made the defaults for Navigations specialisations a bit complicated: (Space) and (Hyperspace) both default to Astronomy-4 or Mathematics (Applied-4); (Sea) defaults to Seamanship-5 or Astronomy -5; (Air) only defaults to Astronomy-5 and (Land) defaults to IQ-5, Cartography-4 or Mathematics (Surveying)-4.

The modifiers are also a bit complicated: the space-based specialties get +2 from 3D Spatial Sense, and the planet-side ones get +3 from Absolute Direction, or a substitute, such as GPS. (Air) and (Sea) are at -5 if the stars are obscured and you don't have a high-tech substitute. Normal modifiers for equipment quality apply, along with penalties up to -10 for an unfamiliar environment; a different planet is at least -5. A magnetic compass gives +1, but I doubt that's cumulative with Absolute Direction.

Navigation is a vital skill for going to obscure and unfashionable places, and shows up on a great many published templates. It's also worthwhile being reasonably skilled at it: Navigation-9 will get you into a lot of trouble. Action 4: Specialists and DF3: The Next Level all provide a lot of packages with Navigation. High-Tech points put that an accurate map is basic equipment for Navigation, an inaccurate map can easily be -5, and no map at all is -10. Infinite Worlds has high-tech navigation equipment that doesn't require external signals like GPS or LORAN, and some discussion of navigation in time travel. Low-Tech expands on the process of navigation, on doing without it via Area Knowledge, and supplies navigational equipment; LTC1 requires Navigation (or Astronomy) to operate an orrery or similar machine. Power-Ups volumes 2, 3, 5, 6 and 7 have examples for this skill and Powers: Enhanced Senses has several abilities that will boost it. Powers: The Weird has a lot on Navigation (Hyperspace), and Space covers getting lost, and recovering from that. Spaceships covers day-to-day navigation in more detail, and volumes 5, 6 and 7 have more tasks. Tales of the Solar Patrol has its own spin, naturally, and Thaumatology: Chinese Elemental Powers has its own helpful abilities. Ultra-Tech has inertial navigators small and rugged enough for personal use. Underground Adventures has the (Underground) specialisation, which defaults to and from (Land) at -2, and gets +2 from 3D Spatial Sense.

Navigation presents a chance for optimisation in much the same way as Guns. As an Average skill with defaults of -2 between the three planet-side specialisations, it's cost-effective to buy the specialisation where you face the biggest challenges at IQ+1 [4], giving you the other two at IQ-1.

In the groups I play in, every character with Navigation tends to roll, as insurance. Yes, critical failures cause confusion, but we have a horrible example from a 3e steampunk campaign that we don't want to repeat. The Maxim Steam Flyer, with one navigator who was also busy minding the boiler and engine, set off from Hamburg in north-west Germany, aiming for Frankfurt in south-west Germany. A critical failure of navigation, misapplying wind corrections, led them to Berlin. Realising the error and critically failing again, with an 18, put them over Prague. Ever since, "Prague!" has been shorthand for "I am not convinced by your navigation."

How have you lost - or found - your way in a game?
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Old 05-20-2016, 03:54 PM   #2
RogerBW
 
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Default Re: [Basic] Skill of the week: Navigation

There are obvious complications and special cases. Navigation/TL8 (Air) becomes much simpler when you're working with GPS rather than with radio navaids (though obviously much more vulnerable to system failures). I'd also argue that if you're used to GPS air or land navigation on Earth, APS air or land navigation on Mars might well be less penalised than -5: in all cases you're telling the computer where you want to go, then pointing the vehicle where the nav system tells you to point it.

I'm not at all convinced by (Space) defaulting to Astronomy. For cruising around the solar system, taking star sights is only a tiny part of the job of working out where you should point the ship, when, and for how long you should burn. Playing with the Orbiter spaceflight simulator (freeware, but alas only for Windows) will make this very clear.

Given that Navigation is explicitly based on map reading, I think one could justify a separate skill for things like orientating oneself by the natural environment (I own a copy of the classic "Finding Your Way Without Map or Compass").

With all that said, I don't have any great tales of navigation in the game. In the WWII campaign it's often made a difference to when the group arrives somewhere, and in my new space game it (a) gives direct bonuses to Piloting and (b) will be useful for plotting cunning courses to shave off crucial hours of transit time.
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Old 05-20-2016, 04:21 PM   #3
johndallman
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Default Re: [Basic] Skill of the week: Navigation

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Originally Posted by RogerBW View Post
Given that Navigation is explicitly based on map reading, I think one could justify a separate skill for things like orientating oneself by the natural environment ...
That seems to be Navigation, or Area Knowledge, going by Low-Tech p50-52.
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Old 05-20-2016, 08:39 PM   #4
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Default Re: [Basic] Skill of the week: Navigation

There are a few odds and sods based in reality that I've thrown out from time to time that throw a spanner into the usual GURPS defaults for my players.

1) Any orienteering above 60°N (or below 60°S) cannot make use of a magnetic compass, but can resort to using an astral compass with ephemeris tables (essentially a land-going sextant with astronomy tables). This switches them from Orienteering to Navigation.

2) In pre-1970 settings, many maps of the north at 1:250,000 scale are blank sheets of paper with a grid system superimposed, i.e. they are featureless. Post-1950, they can make use of inertial navigation systems which give distance and direction from the starting point but require an accurately known starting point to know exactly what your current position is.

3) There is one supposed real-life navigation critical failure that I did manage to use in one game. I'll use the original anecdote though:
Naval midshipman (on a ship in the Pacific theatre): Here are my calculations for our position, sir.
Captain (after perusing the calculations): Young man, kindly remove your headdress.
Midshipman: Sir?
Captain: Young man, we are on sacred soil. By your calculations, we're in the middle of Westminster Abbey.
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Old 05-21-2016, 02:09 AM   #5
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Default Re: [Basic] Skill of the week: Navigation

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Originally Posted by johndallman View Post
That seems to be Navigation, or Area Knowledge, going by Low-Tech p50-52.
Yes, though I think it could be justified as a separate skill or at least familiarity. If you're trained in map and compass you don't necessarily know about the shady sides of trees or whatever, fair enough -10, but that latter thing is knowledge you can learn separately from how to use a map.

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Originally Posted by Curmudgeon View Post
3) There is one supposed real-life navigation critical failure that I did manage to use in one game. I'll use the original anecdote though:
Naval midshipman (on a ship in the Pacific theatre): Here are my calculations for our position, sir.
Captain (after perusing the calculations): Young man, kindly remove your headdress.
Midshipman: Sir?
Captain: Young man, we are on sacred soil. By your calculations, we're in the middle of Westminster Abbey.
I want to use that in a game with teleportation.
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Old 05-21-2016, 07:06 AM   #6
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Default Re: [Basic] Skill of the week: Navigation

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Originally Posted by RogerBW View Post
Yes, though I think it could be justified as a separate skill or at least familiarity. If you're trained in map and compass you don't necessarily know about the shady sides of trees or whatever, fair enough -10, but that latter thing is knowledge you can learn separately from how to use a map.
That would seem to be navigation by landmarks and terrain features, as discussed in Low-Tech for water navigation.
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Old 05-21-2016, 10:04 AM   #7
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Default Re: [Basic] Skill of the week: Navigation

I frequently base IQ rolls for jumper on a specialty of navigation.
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Old 05-21-2016, 11:02 AM   #8
johndallman
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Default Re: [Basic] Skill of the week: Navigation

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Originally Posted by ericthered View Post
I frequently base IQ rolls for jumper on a specialty of navigation.
I don't do that in Infinite Cabal, because the universe is too complex and poorly understood for that at present. Jumper rolls are either to known words, or to get through the barrier between the material and astral planes.

Navigation (Astral), however, is quite important. The astral plane has more than three dimensions, so it's possible to get really, really lost quite easily.
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Old 05-21-2016, 12:40 PM   #9
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Default Re: [Basic] Skill of the week: Navigation

Quote:
Originally Posted by Curmudgeon View Post
There are a few odds and sods based in reality that I've thrown out from time to time that throw a spanner into the usual GURPS defaults for my players.

1) Any orienteering above 60°N (or below 60°S) cannot make use of a magnetic compass, but can resort to using an astral compass with ephemeris tables (essentially a land-going sextant with astronomy tables). This switches them from Orienteering to Navigation.
That is not true at all except for two specific locations on the earth(Near the actual magnetic poles). Any good orienteering map will have a compass correction marked on it, it is part of basic orienteering skills to use it. The big problem is of course that the pole moves and pretty fast so if you are in North of Canada and have an old map...

Further the problem has been getting to be less and less in most places of the north as the magnetic north pole has been going close and closer to the actual pole, it will be interesting to see where it will end up in say 20 years.

Quote:
2) In pre-1970 settings, many maps of the north at 1:250,000 scale are blank sheets of paper with a grid system superimposed, i.e. they are featureless. Post-1950, they can make use of inertial navigation systems which give distance and direction from the starting point but require an accurately known starting point to know exactly what your current position is.
Again it depends on where you are. In Europe there were pretty accurate maps of all of the north in that period. The big breaking point in Europe was WWII as Germans actually did aerial photography of all of western Russia, including the far north, before that some parts there were not mapped.

But the other parts of the north were mapped earlier on. It is true that the level of detail varied from place to place, mostly so that in places with more people the maps had more detail, in places with less people less detail.
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Old 05-21-2016, 12:45 PM   #10
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Default Re: [Basic] Skill of the week: Navigation

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Originally Posted by RogerBW View Post
Yes, though I think it could be justified as a separate skill or at least familiarity. If you're trained in map and compass you don't necessarily know about the shady sides of trees or whatever, fair enough -10, but that latter thing is knowledge you can learn separately from how to use a map.
Survival trivia like where the moss grows is supporting information. It's not the basis of a skill any more than knowing what the pointer on a compass means is...
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