Campaign World... Lot of Advices Required...

[Steel General]

What I usually do, is use Earth's climate as a base, and adjust it as I need or is appropriate to the map I'm working on. Not a very in-depth answer, but it works for me so that's how I do it.

[Karro]

From a strictly technical standpoint, if the world is indeed flat then it will not be subject to the normal forces that affect the real world (such as the coriolis effect and hadley cells, etc.) that create the climate patterns we have here.

So... I'd start at the basics. Despite being flat, for instance, is your world roughly the same size as Earth in area covered? I know you say the seas are "infinite", but you also suggest that sailing off one end dumps you out on the opposite end of the world. Is that true both E/W and N/S, so that if, for instance, you sail too far north, you are suddenly in the south? If that's the case then your flat world is, in fact, being subject to some pretty interesting geometry.

Anyway, if the it's the same size as Earth, does one region still get more sunlight than the other during different times of the year? In other words, do you still get seasonal variations in temperature? (I guess this implies that in summer, the sun-god travels more over the northern sky and in winter more over the southern sky.)

[zenram]

From a strictly technical standpoint, if the world is indeed flat then it
will not be subject to the normal forces that affect the real world (such
as the coriolis effect and hadley cells, etc.) that create the climate
patterns we have here.

1. Is like a 50% bigger than earth.

Is that true both E/W and N/S, so that if, for instance, you sail
too far north, you are suddenly in the south? If that's the case then
your flat world is, in fact, being subject to some pretty interesting
geometry.

2. That's the power of the gods, as they don`t wanna "material" beings on other planes.

(I guess this implies that in summer, the sun-god travels more
over the northern sky and in winter more over the southern sky.)

3. You get it. XD

[Karro]

Okay, this is an academic question, not really one that will help with the climate-placement goal, but if you were to, say, sail all the way north and then just as you were about to cross over into the southern hemisphere you changed directions, let's say made a right turn, where would you end up? Would it still be in the South Pole region only a little to the right, or would it be, for instance, somewhere in the western sea? Additionally... does a compass always point north in this world such that if you followed it and continued to follow it north you'd end up on a continuous loop passing over the same landmark over and over?

Anyway, so you have seasonal temperature fluctuations just as in the real world, driven by where the sun god decides to travel over the world. (Man, this makes me think up some kind of strange plot where a mad king or wizard or something tries to usurp the sun god to keep the sun stationary over his/her kingdoms or lands to make it alway summer there, not realizing the havoc this causes when the rest of the world is plunged into a sunless ever-winter.)

Now, technically in this flat world you wouldn't have the various effects I described that are caused by a spherical world spinning on its access, but might there by chance be a wind god? Given the existence of a wind god, the winds might not be as static as a flat world might suggest, but might flow in roughly the manner we expect based on observations of the real world. Alternately, the wind god might decide to blow solely from one direction, and this would have vastly different consequeneces for the distribution of climates in your world.

But one thing we know, then, is that where we might, if this was a spherical world, roughly find the tropics and equator, we will have a greater degree of heating of the water and air masses - in the summer more heat toward the northern tropics and in the winter more heat toward the southern tropics. Even without being a spinning globe, we might expect some air and water currents to carry the heat and distribute it outward. Depending on the specific geometry of this world, those currents could flow in any number of unusual directions (would an ocean current flowing off the northwest corner of the world end up in the southeast?)

So... you know what... I should stop and ask: do you want to have a level of detail supporting where you put your climates, or do you want something simple and plausible. If the latter, go with what SG suggested: put them where they are on Earth, and handwave any assumptions about what the gods are doing to make them be there. Having them in realistic places in comparison to where they are on earth lends enough verisimilitude.

If you want to go the detailed route, then my next step would be to start mapping out your ocean and wind currents, deciding as you do whether the ocean and wind gods (assuming such gods exist in this world) are following the same principles in place in the real world or are operating out of some other desire. Even if you get effects similar to what is in place on Earth, the geometry of you world could produce some interesting and unusual climate placements, potentially, depending on how you have everything flowing.

[zenram]

Okay, this is an academic question, not really one that will help
with the climate-placement goal, but if you were to, say, sail all the
way north and then just as you were about to cross over into the southern
hemisphere you changed directions, let's say made a right turn, where
would you end up? Would it still be in the South Pole region only a
little to the right, or would it be, for instance, somewhere in the
western sea? Additionally... does a compass always point north in this
world such that if you followed it and continued to follow it north you'd
end up on a continuous loop passing over the same landmark over and over?

1. If you cross over anyone of the edges, you are transported right to the opposite hemisphere, that said, if you navigate all te way to the north and then turn right, you would end in the south sea, but a little to the right... BUT, if you are traveling north just on the northest edge and then turn right, you would end on the southwest sea.

2. Well, i guess the compass can be designed so it can point at the diferent edges of the world, so you can notice the direction you are traveling.

Anyway, so you have seasonal temperature fluctuations just as in the real world, driven by where the sun god decides to travel over the world. (Man, this makes me think up some kind of strange plot where a mad king or wizard or something tries to usurp the sun god to keep the sun stationary over his/her kingdoms or lands to make it alway summer there, not realizing the havoc this causes when the rest of the world is plunged into a sunless ever-winter.)

1. Yes, he travels all around over four close planes Fire-Earth-Water-Air. (The Translation movement of earth)

2. And the Earth God rotates over himself to keep watch over the planes too, so neither of them tries to take over the material plane. (The rotation movement of earth)

3. To mimic at some degree the climates of earth.

4. Good plot. XD

Now, technically in this flat world you wouldn't have the various effects I described that are caused by a spherical world spinning on its access, but might there by chance be a wind god? Given the existence of a wind god, the winds might not be as static as a flat world might suggest, but might flow in roughly the manner we expect based on observations of the real world. Alternately, the wind god might decide to blow solely from one direction, and this would have vastly different consequeneces for the distribution of climates in your world.

1. Well, i have a god almost for everything, very like of those of the greek panteon, and yes, there is a wind god, a fertility god, sea god, river god, sky god, etc...

2. He is a free will spirit, so he likes to travel all over the world constantly, but prefer some places to stick around for a while. (Mimic the earth again)

But one thing we know, then, is that where we might, if this was a spherical world, roughly find the tropics and equator, we will have a greater degree of heating of the water and air masses - in the summer more heat toward the northern tropics and in the winter more heat toward the southern tropics. Even without being a spinning globe, we might expect some air and water currents to carry the heat and distribute it outward. Depending on the specific geometry of this world, those currents could flow in any number of unusual directions (would an ocean current flowing off the northwest corner of the world end up in the southeast? )

1. The currents don't get transported as objects and people, after all they are the sea god, and he can travel wherever he like, but here too, he prefer to be close of de water plane, so the currents usually go there.

So... you know what... I should stop and ask: do you want to have a level of detail supporting where you put your climates, or do you want something simple and plausible. If the latter, go with what SG suggested: put them where they are on Earth, and handwave any assumptions about what the gods are doing to make them be there. Having them in realistic places in comparison to where they are on earth lends enough verisimilitude.

1. Damn, i know im gonna regret it latter but... I wanna have a good explanation to write it.

If you want to go the detailed route, then my next step would be to start mapping out your ocean and wind currents, deciding as you do whether the ocean and wind gods (assuming such gods exist in this world) are following the same principles in place in the real world or are operating out of some other desire. Even if you get effects similar to what is in place on Earth, the geometry of you world could produce some interesting and unusual climate placements, potentially, depending on how you have everything flowing.

1. Well, they follow their desire, but with some logic behind, that logic are the planes and their position in relation of the material plane.

2. When i started the map, i thought in place climates, based on their position on relation with the planes. I added a simple image of my cosmic plan, so you can get the idea. As the plane is flat, you can assume all other planes are flat too, the lines that links the planes are the point of contact between them.