Version 12.0.12+ is compatible with dnd5e v4.2 and up. This wll install even if you don't have dnd5e v4.2 installed, but won't activate. You can install 11.3.64 from the module.json link.
Versions 11.3.19+ are marked as compatible with foundry v12.
Versions 11.3+ are compatible with dnd5e verison 3+
Version 11.1.12 of DAE is marked as incompatible with dnd5e v3.0 and above so you will not be able to activate the module if you are on dnd5e v3.0 or above.
DAE is tested on and developed for DND5E. It may work with other systems, but probably not. It does NOT work with PF2E.
You do not need to use DAE for most of the active effect funcitonality to work. You might choose to use it if you want one or more or of:
- The ability to reference other fields in active effect calculations (core restricts the sort of exressions allowed in active effects).
- The ability to change more fields on characters than default dnd5e allows
- You can call macros, apply CUB/CE conditions/effects as part of an active effect, or apply token magic effects as part of an active effect.
- A different effect editor.
DAE adds some features to core Active Effects.
- Transfer effects (item linked) are now enabled/disbled by dnd5e without support from DAE
- The ability to reference actor data in effect value definitions. i.e. @abilities.dex.mod.
- An extended set of custom fields, like all of the traits.
- The ability to update derived fields.
- A slightly extended active effect editor that provides a list of valid fields, a drop down list of options and drop down lists for restricted fields
Do read the reamd.md on the gitlab, it has lots of information and some of it might not make you more confused.
DAE is known to work with (and has many customisations for) dnd5e/sw5e. It does NOT work with pf2e and will not load with that system.
Other systems are use at your own risk and the utility of DAE will vary widely.