Brian C. said: It is disheartening to see UDL billed as ". . . available with all of the same features as Legacy Dynamic Lighting—and more." UDL has taken a step backward in several areas. Multiple aspects of dynamic lighting have seen significant changes that have a detrimental effect on the play experience or the available options for the GM. DL lines block vision from the edge instead of the middle. First reported July 3 and again here . DL lines block vision from the middle of the line in LDL. In UDL, they block vision from the edge of the line. This means that anything but the thinnest DL lines will obscure more of the map, which is especially a problem when a DL line must be drawn down the middle of a wall or door because the player tokens can approach the line from either side. A thicker line leaves the players wondering, "Is it a door? Is it a wall? I don't know!" It also means that secret doors that were set up with a thicker line than the adjoining wall will leap out at the players when the game is converted to UDL. Additionally, UDL uses more than twice as many lines as LDL for some reason. This means that UDL already has to do more than twice as much work to check where DL lines block vision (and also allowing you to put a token within a wall). Dynamic Lighting walls are jagged LDL works pretty well when only looking at Dynamic Lighting and skipping AFoW. The system runs at a decent speed. It is surprising then that the Dynamic Lighting portion appears to have been largely rebuilt from the ground up for UDL rather than improving on the existing system. In LDL, the system appears to be calculating what can be seen in blocks. In contrast, UDL appears to have traded this for some form of raycasting. At least, that is my guess as to why the unsightly stair stepping has been introduced at the edges of a token's vision (such as in the image above). In contrast, the same DL line gives a smooth surface in LDL. The loss of 5e darkvision I know that not everyone plays 5e, but it represents over 50% of the games played / time spent on Roll20. 5e darkvision allows a creature to see in darkness as shades of grey and in dim light as if it were bright light. LDL did not provide grayscale, but it gave the next best thing by allowing a GM to provide darkvision by setting a token's light to 60/0. This provides dim light to 60 feet, and it combined with other dim light sources to let the player see an area as if it were bright light. In UDL we have 3 options, none of which approximate the level of functionality in LDL: Night Vision provides bright light. Night Vision provides bright light with a visual distortion to show where it ends. Night Vision provides bright light with a color overlay to differentiate it. Option 1 only works for warlocks with the Devil's Sight invocation. Option 2 looks terrible, especially if a player controls multiple tokens and the night vision fields overlap. Option 3 looks nothing like dim light unless you choose black as the tint color. This has the unfortunate problem of having "light" that makes things darker . As soon as two tokens controlled by a player overlap, they completely obscure the map. In UDL, Night Vision with tinting makes a dim light source slightly darker rather than brighter. The loss of "hard edges" on light sources. In LDL, you can make a light source have a "hard edge" by setting both fields of Emits Light to the same value (i.e. 10/10). This is good for a spotlight to point out something on the page and allowed the "full" distance to be bright light rather than fading out. UDL is locked into one width of fading out for the edge. The torch on the left is set to 10/10. The torch on the right is set to 10/blank, which gives the same result as UDL's 10 feet of bright light. I would REALLY like to see some substantive and timely response from Roll20 to Brian's excellent post. Given the above, how can Roll20 justify saying UDL is ready to replace Legacy?