Grid alignment gets easier when you stop treating it as one adjustment. There are really three problems: position, scale, and drift. In Roll20, the new Align to Grid beta handles those through Anchor, Scale, and Fine Tune. In Owlbear Rodeo, enter the map's known row and column count when you have it, or use the visual alignment rulers when you do not. The best test is simple: line up one corner, check the opposite side, then move a one-square token across the map. If alignment gets worse with distance, fix the scale instead of endlessly nudging the image.
A DM imports a dungeon ten minutes before the session. The first room looks perfect. The map grid and the VTT grid overlap cleanly, the fighter token snaps into place, and everything seems ready. Then the DM pans to the opposite side of the dungeon and notices that every line has slowly drifted out of alignment. Walls are cutting through squares, doorways are sitting between cells, and the grid that looked perfect in the first room is nearly half a square off by the last one.
That problem is frustrating because moving the map seems like it should fix it. Usually, it does not. Grid alignment is a combination of scale and position, and the error you see tells you which one needs to change. This guide covers the current Roll20 and Owlbear Rodeo workflows, how to diagnose grid drift, when to use gridded versus gridless maps, and how to know the map is actually ready before your players join.
Why does a battle map line up in one corner but drift everywhere else?
If one section of the map lines up but the error becomes larger as you move away from it, the problem is scale. Your map squares and your VTT squares are not exactly the same size. A tiny difference that is almost invisible across two or three cells becomes obvious once that error repeats across twenty or thirty cells.
Position works differently. If the map is the correct scale but every line is shifted roughly the same distance in the same direction, the map simply needs to move. That is an offset problem. Moving the image can fix an offset. It cannot fix a scale mismatch.
Offset means the whole grid is shifted. Scale means the error grows as you cross the map. Diagnose which one you are seeing before changing anything.
The easiest diagnostic is to choose two grid intersections that are far apart. Align the first one. Then inspect the second. If both are wrong by roughly the same amount, move the image. If the first is correct and the second is wrong, resize the image or change the grid scale.
Should you use a gridded or gridless battle map?
Use a gridless map whenever you know the intended number of rows and columns. That gives the VTT complete control over the visible grid and eliminates the biggest source of visual frustration: two sets of lines sitting almost, but not quite, on top of each other.
A gridded map is still useful when the creator does not provide the dimensions. The baked-in grid gives you a reference that Roll20 or Owlbear Rodeo can match. It can also be useful when the map will be printed, displayed directly on a tabletop screen, or shared without a VTT overlay.
| Map Type | Best Use | Alignment Method | Main Risk |
|---|---|---|---|
| Gridless | Normal VTT play | Use known row and column count | You need the intended dimensions |
| Gridded | Unknown dimensions, print, direct display | Match the VTT grid to printed lines | Visible double-grid errors |
If you regularly run digital sessions, keeping both versions is the cleanest setup. Our Black Lantern Forge battle map collection is built around VTT-ready maps so you can choose the format that makes sense for the platform you are using.
How do you align a battle map in Roll20?
Roll20's current Align to Grid beta is built around a three-step workflow: Anchor, Scale, and Fine Tune. The beta launched for all GMs on August 19, 2026, and the Legacy alignment tool remains available while the new system is still in beta.
Step 1: Put the image on the Map Layer
Upload the battle map to the Map Layer. Roll20 now exposes common setup controls from a Map Layer hotbar, including Align to Grid, grid settings, canvas dimensions, and measurement settings.
Step 2: Anchor a known grid intersection
Launch Align to Grid and place the crosshair directly over one of the intersections printed on the map. Pick a clean intersection that is easy to see rather than one covered by a wall, prop, texture, or shadow.
Step 3: Match the sample grid scale
Roll20 shows a three-by-three sample grid for square maps. Resize it until those cells match the printed cells on your map. Matching several squares at once is more reliable than trying to eyeball a single square because small scale differences become easier to see.
Step 4: Fine-tune any remaining drift
The Fine Tune step lets you correct remaining alignment problems from grid intersections or lines. Roll20 supports manual dragging, one-pixel arrow-key adjustments, ten-pixel adjustments while holding Shift, and on-screen X and Y controls.
Roll20's new core workflow is Anchor, Scale, Fine Tune. Think of those as position, cell size, and drift correction.
When you finish, Roll20 can resize the page around the aligned map and lock the result so it is harder to accidentally knock the artwork out of place. The current tool also supports square, horizontal hex, vertical hex, isometric, and dimetric grids.
If you want the entire setup process beyond alignment, our Roll20 battle map setup guide covers importing, sizing, locking, map layers, and pre-session preparation.
What if you are still using Roll20's Legacy Align to Grid tool?
The Legacy workflow still works during the current beta period. Place the image on the Map & Background Layer, zoom to 150%, right-click the map, choose Advanced → Align to Grid, and trace a three-by-three-square section of the map's printed grid.
Roll20 then resizes the artwork to bring its printed grid closer to the page grid. From there, use the image scaling controls or Set Dimensions for more precise corrections. If every line is shifted by the same amount, hold Alt while moving the map so grid snapping does not fight the correction.
If the first room is aligned and the final room is not, stop moving the map. The problem is almost always scale.
How do you align a battle map in Owlbear Rodeo?
Owlbear Rodeo gives you two main alignment methods. If you know the map's exact number of columns and rows, enter those values directly. If you do not know them, use Owlbear Rodeo's visual alignment rulers to match the scene grid to the artwork.
Use known dimensions whenever possible
This is the easiest option. If a map is 30 columns wide and 30 rows tall, enter 30 and 30 into the manual grid controls. Owlbear Rodeo can also recognize dimensions placed in the filename. A filename containing something like 30x30 can provide the intended grid dimensions during import.
Use alignment rulers when dimensions are unknown
If you do not know the dimensions, activate the alignment rulers and place their origin on a clear map-grid intersection. Scale the grid until several nearby ruler marks match the artwork, then check the far side of the image for drift.
Owlbear Rodeo exposes these alignment controls in three useful places: during scene import, on a map already inside an open scene, and in the Image Editor when changing the default setup for future uses of an asset. That means you can correct an individual scene without necessarily changing every future use of the map.
Our Owlbear Rodeo battle map guide covers the rest of the workflow, including scenes, maps, fog, and preparing the room before players arrive.
How can you tell what is actually wrong with your grid?
The pattern of the error is more useful than the size of the error. Before touching the image again, look at what the grid is doing across the entire map.
| What You See | Likely Problem | What to Change |
|---|---|---|
| Every line is shifted equally | Offset | Move the map |
| Error increases across the map | Scale | Resize the map or grid cells |
| Vertical lines drift, horizontal lines stay correct | Width mismatch | Adjust horizontal scale |
| Horizontal lines drift, vertical lines stay correct | Height mismatch | Adjust vertical scale |
| Edges contain partial squares or borders | Artwork does not end on a grid line | Align from internal intersections |
Why do most DMs make grid alignment harder than it needs to be?
The first mistake is correcting scale problems by repeatedly moving the map. The DM gets the northwestern room perfect, pans east, sees the error, moves the image again, and immediately breaks the section that was already correct.
The second mistake is checking only one corner. A map can look perfect across five squares and still drift badly by the thirtieth. You need distant reference points to confirm that the scale is actually correct.
The third mistake is building the encounter before the map is locked. Tokens, fog, lighting, labels, doors, traps, and other elements all depend on the map geometry. If you discover afterward that the image needs to change size, you have created a second alignment job for everything sitting on top of it.
The stronger workflow is straightforward: establish the intended dimensions, solve scale, solve offset, check the far edge, test snapping, and only then build the encounter.
How do you know the map is actually ready for play?
Do not stop because the grid looks close at normal zoom. Test the map the way your players will use it. Four checks catch most alignment problems before they can interrupt a session.
| Check | What to Test | Pass Condition |
|---|---|---|
| Anchor | Inspect one clean grid intersection | Lines overlap cleanly |
| Far Edge | Inspect the opposite side of the map | No accumulated drift |
| Token | Move a one-square token around the map | Token centers consistently |
| Measure | Measure several known grid cells | Distance matches your game scale |
That final measurement check matters because visual alignment and game scale are related but not identical. A five-foot square should behave like a five-foot square when the ruler comes out. If the artwork looks aligned but measurement is wrong, fix the scene scale before the first initiative roll.
Frequently Asked Questions
What is the easiest way to align a map in Roll20?
Use Roll20's new Align to Grid beta. Anchor the crosshair to a known grid intersection, scale the sample grid until it matches the printed map grid, then use Fine Tune to correct remaining drift. Roll20 can then resize the page around the map and lock the alignment.
How do I align a 30x30 map in Owlbear Rodeo?
Enter 30 columns and 30 rows into Owlbear Rodeo's manual grid controls. If the map was built around exactly those dimensions, this is much faster than visually matching individual grid lines. Including "30x30" in the filename can also provide Owlbear Rodeo with the intended dimensions during import.
Why does my grid line up on one side of the map but not the other?
The map is probably scaled incorrectly. When the difference between the map square and VTT square is small, the error compounds as you move across the image. Adjust the scale before changing the map's position again.
Should I use a gridded or gridless battle map in Roll20?
Use gridless when you know the map's intended square count. Roll20 can provide the visible grid, which eliminates competing grid lines and makes future adjustments cleaner. Use the gridded version when you need the artwork itself as the alignment reference.
Does Roll20 still use 70 pixels per grid cell?
Roll20 currently uses 70 pixels per cell as the default canvas cell size, but that value can be changed. Your source image does not need to have been exported at exactly 70 pixels per square because Roll20 can scale the map to match the tabletop grid.
Can I align a map that has a decorative border around it?
Yes. Do not assume the outer image edge represents a grid line. Instead, use visible grid intersections inside the playable area as your reference. Roll20's current Align to Grid beta is specifically designed to handle bordered and offset artwork more easily than the older workflow.
How do I know my VTT grid is accurate enough?
Check an intersection near one side of the map and another near the opposite edge. Then move a one-square token across several areas and test the ruler across a known number of cells. If the grid stays aligned, tokens snap consistently, and measurements are correct, the map is ready.
Browse battle map packs built for straightforward digital tabletop setup so you can get the map aligned, place your encounter pieces, and start playing.
Browse Battle Map Packs →Sources
| Roll20 | Explore the New Align to Grid Feature in Beta |
| Roll20 Help Center | Sizing and Aligning Maps |
| Owlbear Rodeo | Aligning a Map |
| Owlbear Rodeo | Measure Documentation |
