Hey All, while I love pathfinder, to give my players something new I was thinking of pulling some ideas from D&D 5e specifically when it comes to high level baddies. The things I wanted to start using were things like
Legendary Actions (a list of attacks or abilities that a powerful enemy can use on the players turns with. Each action has its own point cost and a baddie has so many points to use between their turns) Since my guys are getting high level I figure this is a way to make single bosses cool again without adding in a host of minions while letting a baddie not just be pounded on by the 6 of their turns and all the attacks and abilities that implies.
Legendary Resistances (a set number of times per battle, where a baddie rolled a fail on a save, but through their own power can declare that they saved) I am less sold on this as most creature saves in pathfinder are much higher. The only reason that I still considering this is that I did have the experience of rolling the 1 vs a feeblemind spell cast on an ancient green dragon, taking it from an awesome encounter to here is a bag of hit points to wail on until it is dead, but at the same time my guys felt awesome. I figure if I did this then it would need to replace spell resistance.
Lair Actions (Makes it more of a threat to attack a big bad in their home base. And again adds more to the action economy of a big bad to the mix. The place seeped in their power gets a turn and different environmental effects occur)
So here is my question is this. As I am not a numbers person does anyone have experience with this and what kind of adjustment in power level it would create? I don't want to make it an outright death to players, and because I want to award appropriate experience points. Usually I can do well with the experience point budget system, just want to add something new.
I've had a little experience with adding Legendary Actions and Lair Actions to PF, and it's never been a problem (but I've never done it on the fly, always been careful to consider the ramifications).
I haven't tried Legendary Resistances, though I might if the opponent were at deity-level. I actually think the big bad rolling a 1 on a save is a pretty epic event at the table in itself, and I'd rather not take that away from the players.
For the record, I imported a lot of the little rules in Torchbearer (encumbrance via slots instead of weight; downtime stuff) and a lot of the player vs. player role-playing stuff from Hillfolk (w/ house rules; rewarding PCs for choosing non-optimal outcomes with Pathfinder Plot Twist: Flashback cards).
I cannot tell you how tempted I am to import the much simpler Wild Shape rules from 5e, but I haven't quite had the guts to do it yet.
I use Inspiration as a role-playing reward, and frequently give advantage at the table when I'm pretty sure (but not positive) a character should be able to succeed at something (or vice-versa, disadvantage).
Legendary Actions is just Combat Reflexes with Zest. It shouldn't really affect CR that much.
Legendary Resistance should probably be used as a plot point or story saver. For example, if the big boss fight would end in 1 round because of a single failed save, you've wasted a lot of time planning the encounter, and you're wasting your players' time since a really fun encounter became blah. Maybe call it a Fate Point, and the BBEG can spend it to auto-save or ignore a critical hit, or even to reduce damage from -50 to 1 hit point. Especially if it would enhance the fun for everyone!