This is about a Roll20 feature exclusive to Plus & Pro-subscribers, or to players in a Game created by a Plus/Pro-subscriber. If you'd like to use this feature, consider upgrading your account.

Roll20 currently have two Dynamic Lighting systems, which are not interchangeable.

Legacy Dynamic Lighting

Legacy Dynamic Lighting(LDL) is the original system, previous referred to as just "Dynamic Lighting", and is what people talk about in any guides or videos made before April 2020. It will eventually be removed when UDL is good enough.

• Advanced Fog of War(AFoW) - A part of LDL

Roll20 have announced that LDL will be retired on May 18th 2021. More info: LDL retiring - What you need to know^(Blog)

Updated Dynamic Lighting

Updated Dynamic Lighting(UDL) is the new DL system Roll20 have been working on to develop as a replacement for LDL, and it was first made available in May 2020, and as of Feb 2021, still have some unresolved issues.

• Explorer Mode is UDL's equivalent to AFoW
• Darkness Tool is a tool that can be used to manually reveal or hide visible areas while using UDL. Fog of War is the free version of this tool, which is compatible with LDL
• Convert Lighting Tool - for one-way converting Lighting settings & tokens in a game from LDL to UDL. Recommended to be used on a copy of your campaign, as you can't change things back with a single click.

General Info

On both Tokens and the Page Toolbar, the setting for LDL and UDL are on separate pages, as not to confuse people.

Roll20 have announced that LDL will be retired on May 18th 2021.

API

This is about a Roll20 feature exclusive to Pro-subscribers (and often to players in a Game created by a Pro-subscriber). If you'd like to use this feature, consider upgrading your account.

Some API, such as TokenMod, support both LDL and UDL. There are still some UDL settings that API cant currently access.

Check API:Script_Index#Dynamic_Lighting for list of some API that focuses on DL.

A number of API automatically detect which DL is used, and acts accordingly.