drawing a map as you go (whiteboarding)

Hello All, Is there any way in Roll20 to draw a map as-you-go? In our AD&D campaign (long-running, moved online this year) we use a whiteboarding app. It works, but it's not game-oriented. I would like to move us into Roll20 but that puts the heavy lift of pre-creating all the maps on the DM (which isn't me right now) and that's not gonna happen. Any suggestions? Thanks!

There are a host of drawing tools built in, and you can certainly use them to sketch out maps as you go.  That's the way i started using Roll20.

If the terrain is very similar (say, a dungeon floor), you can do a pretty convincing map just by tiling a large dungeon floor texture on the map layer, concealing the page with regular Fog of War, and "revealing" rooms and corridors on the fly. Thinking back to years of making tabletop dungeons with pencils, book edges, and scraps of paper, and populating them with dice monsters...

The biggest thing to be aware, can be considered a limitation for this, the Page size cannot be expanded infinitely (there is an indefinite size ceiling), and all expansions of page size originate from the Top Left growing outward, not from the center. Best technique for whiteboarding in Roll20: Start off with a fairly Large size page (I personally would do at least 50x50 but you could get away with 25x25 or 40x40).  I recommend a non-white background color such as light grey or dark grey, or dark brown, it's easier on the eyes.  You can have the Grid turned ON or OFF, showing or hidden. Have everyone start the mapping from the Middle of the page, or from the Lower Right side (which can be expanded out when needed). Don't start their map at the upper-left unless there's no chance of the dungeon expanding Northwest.  You won't be able to grow more open space in North or West direction. Good news you can make Unlimited Map Pages in your roll20 game.  When you feel that you reached the edge, need a blank slate, or want to continue the dungeon onto a fresh page, that's free & easy. The drawing tools has Shapes (rectangle, elipse), Polygon Lines that can Snap to the Grid or NOT, and Freehand drawing pencil. Each player's drawing defaults to that Player's color swatch (their choice), and anyone can change their drawing color(s). There is not a built-in way to prevent a player from drawing, they would all have the ability to draw, it would be up to the GM to tell them socially who is supposed to be drawing.  With a paid subscription you can use an API Script that automatically hides-erases-name-labels any drawings, if you must prevent scribbling.

All great information - thanks. I will dig in this weekend and get my feet wet. @keithcurtis we've been using battle mats forever!

Works very well, thanks for the hints. I had poked around in the interface and watched videos but never simply started a game and went through the tutorial. Very, very cool. Thanks again!

I'd like to follow up on this because I'm looking at starting a gritty dungeon-crawling campaign where the only maps the players see are the maps they draw. My plan: Each page is a physical sheet of parchment/vellum/hide/whatever. A physical map. The character that possesses the map is the primary mapper. If the character dies and their possessions are lost, the maps are lost too. Players will come and go between sessions. If a character isn't in the current group, their maps are not available. If the group splits up, well, someone's probably getting lost. If the party is in town, characters can copy maps. My plan so far is: Create a base "blank map" page. When a character declares they are mapping, create a new page and label it with character name - map name . The players are responsible for noting links between maps (pages) and asking to move to a new map when needed. If a player copies a map in town, duplicate the page and rename it. My bugaboos: I really dislike that draw color is fixed to player color. This usage needs a real drawing palette with a remembered color. I wish there was a way to stick the drawing palette on a floating dialog so it wasn't always hidden in a menu. Anyone see any ways to improve this?