If so, this would definitely give me a reason to buy more lieutenant packs. I know with the campaign, they would only show up occasionally as major peril, which is cool if you have them, but not quite worth buying them for that reason.

If they're more involved in the Delve, then I just may have to look into getting some more lieutenants.

The Delve uses lieutenants from whatever expansions you have, so by default you're going to have a cardboard token for whatever it throws at you.

The only difference you're going to see if you have a lieutenant pack is that you will be able to use a really nice miniature instead of a token.

This is a HUGE bonus if you already have lieutenant packs as ordinarily most do not see play in RTL in the previous campaigns.

As to whether it is worth the cost of a lieutenant pack to field a miniature, that's entirely up to you (for me my completionist and aesthetic sensibilities mean it's a must).

It's also worth noting that there is a difference between a lieutenant and an agent ... when "lieutenants" appear as a peril in RTL, they appear as an agent, not a lieutenant (slightly different abilities/stats)

So lieutenants show up in the Delve solely based on the box expansions you have rather than the lieutenant packs? I was considering buying some lieutenants that I did not have the box expansion for just to have more variety with the boss levels.

So lieutenants show up in the Delve solely based on the box expansions you have rather than the lieutenant packs?

Yes that's exactly right.

For example if you have Manor of Ravens you may run into Skarn in a boss fight irrespective of whether or not you own the Lieutenant pack.

The Lieutenant pack is giving you a cool miniature and the ability for Skarn to appear as an Agent when peril is high.

Thanks for clarifying that.

The other day I had Serena in my party and ... was given her "Boss Stage" - not game breaking, I mean if you've got good Serena/Raythen and you're only going to be presented with the evil clone, but it'd be really nice if the Descent App would take your party composition into account and avoid that stage when appropriate.

Spoilerific note on the stage below...