It is difficult to succinctly describe what idle Champions of the Forgotten Realms actually is.

The core gameplay loop is a sort of Sudoku-like puzzle, where you fill a fixed grid with characters, who attack enemies continuously and automatically, with the aim of maximizing the amount of damage the formation can pump out. The characters you collect all provide a suite of upgrades, but their usefulness will depend on where they're placed in relation to each other and how much they like the stats/alignment/race/etc. of the other characters you're using and/or the enemies you're attacking.

But then on top of this foundation are layered multiple levels of meta-progression and collection, all of which serve to raise the floor and ceiling on the amount of damage a given formation can produce. These range from the obvious (collecting the champions and their equipment) to the thematic (currying influence with various deities and patrons) to the ridiculous (collecting pipe pieces you can fit together to pump liquid through a robot heart, which not only gives upgrades but allows you to automate various tasks in the game).

And then on top of all of that, there's a community built around streams of players and devs playing the game to explain the meta-progression systems, and people actually playing DnD, and weird creative shows where they create pancake art or make songs about characters, all of which feed back into the game itself by spitting out chests of equipment and buffs.

This is all before you get into the minutiae of how to farm stacks for persistent character boosts, build speed formations to clear content faster, farm tremendous amounts of gold using Azaka, or play around difficult party restrictions imposed by advanced adventures.

I like this. This is my jam. I know next to nothing about Dungeons and Dragons.

There are faults. Or perhaps more accurately caveats.

The game itself is opaque, communicating what buffs and debuffs are active through unintuitive iconography and a menu system that is difficult to understand as a beginner. It is necessary to engage with the community to find resources on how characters and systems work after only a few adventures if you want to progress.

Although this is less the case with newer content, I find some adventure variants are simply punishing and un-fun (e.g. click-damage checks, all-armoured enemies), or just monotonous (basically anything where it's just "some positions are unavailable"). There is so much content available now that it is not strictly necessary to engage with all of these to reach the late-game, but that volume can also seem daunting if you're just starting.

Bugs are ever-present, and accumulate as new mechanics are introduced and interact with the old ones.

While free to play, I am not sure to what extent the game is tolerable over the long term without investing in familiars. At time of writing, there are only 11 of these that can be purchased using the farmable currencies, and most of those require advancing to the late-game or playing for an enormous amount of time before they can be unlocked. While familiars are nominally a quality of life upgrade, if you want to take advantage of the automation mechanics (which speed up progress considerably) you will need a number of them, and 11 is on the low end of what I'd consider comfortable. (Auto-clicking scripts are permitted and there is a community focused on their use, but they are not supported and patches may break them.)

That being said, the advantage of the model is you are able to spend up to whatever threshold you are comfortable with.

I played this game on the Switch when it was released on the console, but found it chugged significantly and the interface was cumbersome to navigate. I changed to Steam and have not looked back. Having logged several hundred hours at this point, I don't see how I would enjoy the game if I was not able to run it as a background process.