A good option is: Use the grid that is mostly aligned, but which gets "off" alignment after a certain distance. Make the alignment as close as possible, and then make Roll20's grid invisible. Change the Roll20 Grid Opacity to zero, transparent. The setting is called Opacity . Here is the wiki docs, <a href="https://wiki.roll20.net/Page_Settings#Grid" rel="nofollow">https://wiki.roll20.net/Page_Settings#Grid</a> In this method -- You will SEE the grid that is on the WOTC map, but Tokens will move & measure according to the invisible Roll20 Grid which is only slightly off, and which is only off in some parts of the map anyway. It should look fine with the Tokens on the WOTC map and Players will hardly notice that tokens standing on the far-side of the map are standing on the cracks between the floor-stones (standing slightly over the WOTC grid lines, rather than directly in the middle of the WOTC squares). In some ways it may look even more natural like this, since people commonly straddle the crack in the sidewalk. Since everyone will be consistently and officially using the Roll20 Grid measurements and movements, all the tools for moving and measuring should work fine, with only slight slight discrepancy from the WOTC visual background scale. "Hey that looked like a 25' wide room but Roll20 measures it as only 24.5 feet across!" The discontinuity will probably be around 1 foot, if that, so just be sure to declare that the Roll20 measurement is the official distances in-play in-your-game.