The physics and characteristics of the planet your story takes place on will be more important in SF, particularly in multiple planet systems, than other genres, and is more important in novels than in shorts. However, whether you get detailed and figure out your gravity per square inch, or just do some general basics, having an idea of how things work can help you with your world building. The characteristics of a planet will determine the type of life found there and, conversely, the type of life you want on a planet will help determine what characteristics your planet needs to have. The physical make up of your world will determine how life develops, what kind of defenses it has, and so on.

So, your first question for a non-Earth based story is what kind of star will it take place on. The kind of star you use will determine its diameter, the level of heat it radiates, what kind of atmosphere it has, it's tidal forces, and so on. The choices you make determine whether or not the star can support the kind of life on it that you want. Even if you don't need to know the specifics of the star, it's a good idea to have at least a general idea about different kinds of stars. You need to at least have an idea of how your star differs from our own world.

How far is your world from its sun? How big and hot is its sun? If you're not careful, your planet could be too hot or too cold to support human-like life. How big is your star? What is it made of? A core of iron or nickel affects gravity and magnetism. A low metal planet can have a magnetic field so low that it doesn't turn a compass. And a low metal planet won't have a whole lot of metal products: things on earth that are made of metal would be made of other things on a low metal planet.

What is your planet's orbit like? This will determine the length of its year and seasons. Rotation affects length of the day and how much heating and cooling the planet experiences, and thus also affects the weather experienced. Axial tilt determines how much sun a particular region receives and is responsible for climate zones and seasons. The more tilt your world has, the more extreme its seasons and the more even the global climate.

What kind of gravity does the world have? Contrary to popular belief, someone raised on a low gravity world wouldn't go springing 20 feet into the air with little exertion because he or she will be used to the level of gravity he or was raised in, much as we are used to Earth's gravity. The inhabitants of a planet will have a musculature and body form suited to that environment. However, where the characters were raised will make a difference in a multi-world story. Taking a creature used to a low gravity world into a higher gravity world will affect its movement, and vice versa.

How many moons does the world have? How big are they? Do they vary in size and distance? How do they affect the tides? Do they have an atmosphere? Do people live on them? Is the world your story takes place on actually a moon itself? What kind of orbits do they have?

Water is the one requirement we know of for life, so how much water is on your world? What kind of atmosphere does it have? How do they both renew themselves? On earth we have an oxygen cycle: we breathe out carbon dioxide, plants use it and produce oxygen. Water evaporates, condenses in the air, and falls as fresh rainfall. If you want non-oxygen breathers, it is possible, but it will take work on your part. You will need to research chemistry and biology to make it believable. But life without water will be a lot harder to make work.

Then there is what is known as "special physics." With the blending of genres, every author needs to decide if their world has special physics. Special physics includes things like faster than light travel, magic, extraordinary creatures, deities, anything that's outside our accepted idea of what's real in the world. Which is not to say things like magic and angels aren't real, but according to today's thinking they aren't. If your book will touch on the supernatural, the magical, the mystical, future/non-existence technology, time travel, magic itself, even something as small as deciding the existence and composition of angels, you need to think about special physics.

First you need to decide how your world differs from the real world. How did those differences come to be? Are they worldwide or do they affect only a small region? How do they manifest themselves? Your special physics will needs laws, guidelines to how they act and can be used. The laws you decide on will determine what the special physics can and can't do, how they do it, and how they can and can't be used.

Once you get that down, you have to figure out how they affected the development of your world. Resources on your world will be used. If it's a resource like magic, it will affect the development of the world's organisms and have an influence on culture and history. What kind of people can use this special resource? How do they use? How long have they been using it? If they've been using it for a long time, it will be more pervasive in the world. If it's fairly new, there's going to be more mistakes made with it. How are the people who can use the resource different from those who can? What makes it so they can use it and others can't? How do those who can't use it view and treat those who can?

Now that you have the basics of your world down, what kind of star it's on, the laws that rule it, and an idea of what the special physics are, it's time to get a visual idea of it down. I've been done a lot of mapping in my life; it's one of the positive affects that being a table top role player and game master for over 20 years has had on my writing. I'm going to discuss floor plan maps as well as world maps and get it all done together. But don't worry if you can't draw or don't have any mapping experience - the maps you create are for you and no one else. When your book gets published, the publisher will, more than likely, have a pro create any maps needed for the book. Perfection is not what you're really after here. You just want a representation you can refer to when writing and/or revising.

Everyone should use maps - world maps, city maps, and building floor plans. The longer the story, the more locations you have, the more maps you will need. Maps help provide consistency by giving you a resource to use when you forget a fact about a place. Rooms won't move, people won't walk out onto thin air, cities won't change size from one chapter to the next. When I first wrote my book, I didn't have a clear idea of one of the buildings, which was a ruin. When I sat down and thought about what my characters had just done in one chapter, I realized they had just all walked over a section where there was no floor . . . and they did not know how to levitate.

For real locations, find maps that accurately reflect the area for the time your story takes place. If your story takes place in a fictional world, you get to create the maps. You'll want world maps, a map of the country and/or state the story takes place in, the city, and maps of the buildings. If you need some help or ideas take a look at real maps, preferably the flat type rather than globes since you'll be creating flat maps. Look inside some of your favorite novels and study blueprints. And an excellent resource is gaming adventures. Pick up at least one AD&D adventure to use as a reference. Most should come with both dungeon/building maps and terrain maps.

If you're still self-conscious or a perfectionist, you can use software. There's a number of mapping programs, one of the most popular (and with symbols that most of us fantasy readers will recognize) of which is ProFantasy. PF is rather expensive, but, from my understanding, is well worth the cost. You can purchase add-ons that do world, city, and building mapping. And the end result looks very "Tolkienish."

If you can't afford to pay for software, there is a free option: AutoREALM. I've never tried it, so I can't really tell you anything about it. Two other programs include QuarkXPress and nbos. Quark isn't specifically for mapping, but I've heard of places that use it. I don't really know anything about nbos.

I do recommend giving hand drawing your first map a try, if only to save time and money and to keep from procrastinating. You'll need graph paper for starters. You CAN use plain white paper, but graph paper allows you to determine distances by making each square equal to so many feet or miles, which is very useful if your characters have to travel anywhere. My choice for indoor maps tends to be 5' per square. Outdoor maps vary. I prefer graph paper that's 10 squares per inch, although 8 squares per inch works too, and has darker lines at every inch mark. Take a look at this graph paper sample for an idea of what I mean:

There is a place that offers printable pdf's of graph paper online, but I haven't been able to get them to actually print correctly. However, one of you might, so here's the url: http://www.incompetech.com/beta/plainGraphPaper/

This type of paper tends to be pretty cheap, particularly when bought in bulk. You could also try larger architectural papers, if you can find them. however, they tend to be more expensive, if a bit more fun. I once had a city done in larger sheets of architecture paper that covered my entire living room floor.

You will also need the following drawing utensils: a soft, easy to erase pencil; a fine to medium point, black, felt tip marker; colored pencils (blue, green, brown, sandy colored at the very least); a blue, fine point, felt tip; a ruler or some other straightedge; and, if you're working on indoor maps, architecture templates like these.

Even though you're not trying for perfection, you'll want to be able to erase until you have your map's features pretty well determined, and you don't want eraser marks. That's why you want an easy to erase pencil. Soft pencils also allow you to create some really light lines as well as some darker lines. Number 2 pencils work as long as you can erase them easily. Mechanical pencils have never worked well for me.

The black felt tip will be used to darken and finalize your coastlines, walls, and so on, so you don't want it to be too thick. I've recently started working with 2 thicknesses, one for the coastlines which need to be very dark, and one for the topographical features that basically need to be darker than black ink pen, but not as dark as my coastlines. Regardless of your choices, make sure ANY ink you use is smudge proof or you'll be very unhappy with the results.

The colored pencils are for your topographical features - lakes, mountains, forests, and so on. Drawing them in pencil, make them permanent in black ink once you're happy with them (with a couple of exceptions), then givie them their appropriate color. An exception is lakes and rivers, which the blue felt tip is for. For lakes, I outline in blue felt tip, then color in with blue pencil. The colored pencils should NOT be easily erasable. If you care about quality, I recommend Berol Prismacolors.

The shape templates are particularly useful for floor plans, especially circles and hex types as they can indicate pillars. Unlike world maps, floor plans do tend to be a bit more neatly done, perfect if you will, and well planned. If you want to go that far, there are even furnishing templates out there. The templates I use are Staedlers.

Finally, have either a scanner or a place where you can go get photocopies, especially for world maps. I highly, HIGHLY recommend copying your maps between each stage. Keep copies of every stage and of any future changes you make. If you need to go back a step, it is so much easier than having to do the whole thing over. Trust me.

Okay, let's start with the basic process of mapping a world map. One thing to keep in mind before we get started is to make sure to research anything you need, from weather patterns to continental drift. This map may be just for you, but you do want it to be accurate or it's not useful for your writing. First, mark north with an 'N' and an arrow pointing towards it. If you look at the mapping symbols image I've provided, you'll see an example on the right. Usually north is towards the top of your map.

Now, with your pencil, lightly sketch in you continents. They don't need to look like anything in particular, and they don't need to look perfect. Try to incorporate "mistakes" rather than "fixing" them. Some mappers work this step in pen, but I just can't do that. Every now and then you have a specific idea of how you want something to look and need to erase. Once you're satisfied, go over your pencil lines with the black felt tip, then photocopy or scan the map at least once.

Next, using the pencil again, mark your equator with a single, VERY LIGHT, straight line. Now, again in pencil, add topological features: forests, rivers, mountains, marshes, deserts, hills, and lakes. If you look at the mapping symbols image again, you'll see some simple, easy to draw symbols you can use for these features. Keep in mind that water flows downhill, so your rivers will more than likely go from the mountains down to lakes and the coastlines into the seas. Mountains are created where tectonic plates meet. The windward side of the mountains will be wetter than the leeside, and mountains block wind, making the other side much drier and you're more likely to see a desert there than on the windward side.

Once you have everything penciled in and are happy, use the thinner black felt tip to carefully darken the lines, except for lakes and rivers which should be darkened in blue, and the equator which should be kept in pencil. If you want your equator unerasable, then make sure any pen you use is very light or in a completely different color than anything else on the map. Then photocopy or scan it again.

And now you can color, if you want. Try using variations in color to indicate differences - dark forest green for snarled forest no one goes into, light green for those woods that are pleasant, olive green for tropical forest. It's up to you. But, once you choose a particular color to represent something, stick with it. You may even want to write a legend on another piece of paper.

Once you're done coloring, photocopy or scan yet again. Then, using the soft pencil, do faint dashed lines to indicate wind patterns. Use an arrow to indicate the direction the wind blows. Finally, for this stage, draw faint lines indicating where national boundaries are. When you're happy, photocopy or scan it again.

Now you get to do little details. Name things (and, yes, write names ON the map): the nations, the landmarks, etc. Indicate cities and towns and mark each nation's capital, name them all. How you will do this will depend on the scale of your map. If you can, you want to do more than just mark cities with dots and 'x's. Use buildings, if possible, show streets, indicate gates and walls - and make city walls thicker than castle walls if you can. However, the scale of your map may not allow this. Alden's scale is such that I can't do this at all.

What I have to do is take sections and create enlarged maps for them, both on a national and local level. And that's fine, more work, but fine. It's a good idea to do this kind of thing anyway, if only because it will allow you to add details you can't really fit in on a world map.

You don't need to do all this at once. Do what you need for your story, you can always fill in as you go. But do keep in mind that surrounding areas impact a particular location. No one place or person is completely isolated. Once your map is done, you will have a wonderful resource that you can look at to help you keep your writing consistent. I use my Alden map frequently for everything from determining how far away places are from each other to determining directions.

Now, let's look at how to develop a floor plan. You'll notice on the image I've provided that I've marked north just like we did for the world map. Do this for all your maps. With this one, you'll notice that the arrow is next to the 'N' and that's okay. The important thing is that you can tell direction on your map.

Before you get started with the actual floor plan, you need to decide a few things: how many rooms will it have and how many levels. Are there unusual features or rooms with unusual purposes (such as a demon summoning room)? Do you want the building to be a particular shape, an L-shaped house for example? And what kinds of features are around the building - other buildings? Fountains? Trees?

Once you have an idea of all this, draw the basic outline of your building - outer walls only. Add any topographical features around it (if there's a cherry tree right by the door in chapter 1, and no one cuts it down, you better not forget about it in chapter 5). If you have multiple floors for this building, you'll work one floor at a time starting with the ground floor., notating which level each map represents.

The first internal structure to indicate is the walls of rooms. Use spaces to indicate doorways without doors, and narrow rectangles to indicate doorways with doors. Windows, as you can see on the sample map, are two lines perpendicular to the walls that indicate the outer boundaries. Keep it fairly simple. Once the very basics are down, add anything that connects floors: stairs, laundry chutes, elevator shafts. When you work on the next floor, after you outline the building, you're going to want to draw these in first to make sure they get in where they need to be.

Now you can detail the rooms: use wavy lines for curtains, dashed lines for blinds, draw in any built-in features such as pillars, sinks, and bookshelves. I use a different color for furnishings to differentiate them from built-in stuff. When you have the details in, label the rooms. If a room has a special purpose, give it a name and indicate on another piece of paper what goes on in that room.

When it's done, be sure to darken the lines with your black felt tip again. Then you start on the next floor, and here's where graph paper can come in handy. Even if the next floor up doesn't cover the entire ground floor, lightly sketch it in anyway, making sure the number of squares used per wall matches. Then add your stairways and elevators and so on. Now, with stairways, you're only going to show the "top" portion of them, and you need to take them out at least 1 or 2 squares further than what you have drawn on the previous level. This is because stairs no only go up, they also go forward - if they didn't they'd be ladders rather than stairs. After you have the connecting features between floors done, detail the rest of the level as before. Do this for as many floors as your building has.

Mapping makes your world easier for you to see and use, and helps to keep your writing consistent. Start researching and developing your world maps and the floor plan of the first building that appears in one of your longer works in progress. If you're doing Scifi, you can try your hand at a ship plan rather than a floor plan. And when you have your maps created, make sure to use them. Your writing will be better for it.