D&D 5E Legendary and Lair as tools for every level.

[Joe Liker]

On the subject of not overtaxing player resources, automatic saves should be limited to 1 per tier per day.

Two resistances or one immunity per tier seems appropriate.

(Yes, there are tiers in 5e, but I can't remember the level cutoffs.)

 

[Mistwell]

What do you think about it?

As I see this, legendary traits and lair actions are a mechanical way to create memorable boss fights, but memorable boss fights can happen at any level. If I give the CR 2 orcish warchief a lair and some legendary actions instead of a bunch of sidekicks, am I inviting a TPK?

This is what I have been doing.

In fact, I do it for even non-boss fights, for solos sometimes. I just did it on the fly for a single mummy, because otherwise the encounter would have been over in a single round.

 

[Quartz]

If I give the CR 2 orcish warchief a lair and some legendary actions instead of a bunch of sidekicks, am I inviting a TPK?

I would be very careful. At CR 2, presumably the PCs are level 1 or 2, so it doesn't take much to swing the fight. Something along the lines of 'can shift 10' (towards the exit)' might be good.

 

[Nebulous]

I've been thinking of doing exactly this, and I rather hope there are some suggestions for it in the DMG section on modifying/building monsters. I love the idea of, say, a legendary wraith or doppleganger. And giving lair actions to a ghost is a great way to simulate a haunting.

I haven't figured out how to do it so it's not unbalanced, yet, but I'm sure it's possible.

I think this is a great idea, and you can take any mundane monster, like an orc, and make him an Orc Chieftan with a few legendary powers. It would be even more awesome if the Dungeoncraft monster builder had a library of powers you could swap and mix and match.

 

[Fion]

A CR 2 enemy is a hard challenge for a party of 4 level 2 characters. CR 3 is deadly.

I can see using a CR1 creature such as an Goblin Boss, give it lair actions or a legendary action as a solo fight it'd be very solid challenge. But add minions and your difficult boss turns into a TPK.