What resolution/size should I make my map for publishing?

[cheepicus]

Hi everyone. This is my first post

I've got an offer on the table to make maps for a published product (an adventure module for an RPG). This is my first cartography-type job.

I don't know what size the maps will be on the printed page; I've been told some of them might be as big as "poster size" which is I assume is 17"x22" or A3. Not sure if "poster size" is a term of art.

The original maps themselves were made on Letter paper but might change or require a little more space than that. (I.e. the client's hand-drawn maps didn't have to worry about margins.)

So I'm trying to figure out what resolution and size to make these maps to work on. I guess I do 300 dpi 17"x22" so that they can be printed out on posters if it comes to that, or shrunk down to Letter size if needed.

Oh wise Cartographers' Guild, am I on the right track here?

[tilt]

lol... well, posters do come in many sizes - a standard in europe is 70x100 cm, but that is but one size possible. If you map in vector size is of course no object, but since you ask I'm guessing you use raster (ie photoshop, gimp etc). If so then, as you say, multiply the size by 300 dpi for professional printing in high quality, 200 dpi might be enough for some types of print so if you can ask the publisher what they need you might have a smaller job to work on memory-wise.