I am near the end of a 4th edition Dungeons & Dragons campaign, planning to start a new campaign in 5th edition. As there are several fundamental design differences between 4E and 5E, I need to rethink the way I do some things. And that includes the use of maps.

4th edition D&D works with big tactical encounters, usually involving several types of monsters and a tactical map designed to add spice to the combat. So what I did for 4E was printing those maps at the classic 5 feet equals 1 inch scale. Smaller maps I could create and print with software like Campaign Cartographer. Larger maps I would be using a poster printing service to have them printed on poster paper. Not the cheapest option, but then those large fights might take hours, and so I considered that worth it.

5th edition D&D works very differently. A typical adventuring day has more encounters, but many of them are smaller. Sometimes you get tactical encounters with more monsters, but sometimes you just fight two goblins. There is also more flexibility to add additional fights in the form of random encounters. Fights are short, and printing out the maps doesn't seem worthwhile. So for those small fights, a neutral battle map on which you quickly draw the environment is sufficient. I ordered a vinyl map for greater durability, and I'll get some dry erase or wet erase markers to draw.

However 5th edition much more than 4th edition works with dungeon maps having lots of rooms. There are a lot of different systems that dungeon masters use for that: Some draw the map as it is explored for the players, or draw the rooms for fights and let the players draw the map of the whole dungeon. Some use tiles. Some print out the dungeon map, then cover it with something (I've seen everything from sand to post-its used) to reveal the map slowly. And some people play online on virtual tabletop software that automatically calculates line of sight or lets the DM unveal the map in other ways.

So I was thinking that I should be able to do something like the virtual tabletop, but using just a tablet it put in front of my DM screen. I load the image of the map, cover it in black, and then uncover the areas the players explored by erasing the black. I tested out some apps, and on the iPad the Paper app works pretty well. On Android I found that the free version of Autodesk Sketchbook does the job. Basically any painting app will do, as long as it allows importing pictures and using layers. You just add a layer on top of the map, paint it black with a big brush, and then use the eraser to reveal the map.

As an aside, I am planning to use random encounters a lot more in 5E, because they can be a solution to an old problem: Some players like to use all their resources at the first sign of trouble and then insist on doing a long rest after each fight to recover spells and the like. The DM of course can always manually intervene, or create some time constraint in the story that makes frequent rests unfeasible. However that often comes over as heavy-handed.

So in my new 5E campaign I will have a simple rule for long rests: After every 2-hour watch, the player standing guard will have to roll a d20. On a roll of 1 to X, a random encounter happens, with X being how dangerous the environment is. Sleep in the middle of a kobold-infested warren, and X can be 5 or more (giving a chance for at least one random encounter of 68%). A relatively safe location only results in a random encounter on a roll of 1 (19% chance).