Apologies if this has been covered already, but I plan to incorporate both the hero points and inspiration mechanic in my campaign. Curious to know your experience with these mechanics... Is it good/bad to use both or either? Thanks.
I don't like when the DM uses hero points or action points, mostly because they always feel too "meta". The only narrative explanation is typically "because you're heroes so you sometimes get to negate the odds".
Sometimes I feel that the problem comes from the game being too easy. If most of the time the PCs succeed at what they try to do, then failure really stings when it happens because of a bad roll, and therefore many players want a trick out of that situation. That's my short explanation about why hero/action points are actually pretty popular.
Note that I am not against using PC protections in general. As a DM I sometimes have players who clearly don't want their PC to die, and I have decided long ago that I will always let them stay alive (e.g. by replacing the event of death with some other penalty) if dying would seriously upset the player. However, hero/action points always feel too artificial, too much like "that was bad luck... so let's pretend it didn't happen". Why even rolling the dice in the first place then?
On the other hand, when I prevent a PC's death, I'm not "pretending it didn't happen", instead I am just voluntarily interpreting the condition "below 0hp" (or whatever defines death) as "death or something else, depending on the circumstances", and follow up with a narrative explanation (the penalty the PC gets is related to whatever caused the fatal blow).
That said, 5e
inspiration is a lot better for me than mere hero or action points. The reason is that
inspiration is much more solidly tied to the narrative, since it is gained usually by doing something in-character and feeling morally boosted afterwards, while in the most common case hero/action points are just a fixed daily pool.
I haven't actually used
inspiration yet, but when I do it, I will however probably end up using it more sparingly than the other DMs out there. More specifically, I intend to grant
inspiration mostly only to someone purposefully having her PC do something
inefficient/inconvenient just because it feels more in-character compared to the most efficient choice. So you can either go for efficiency (which has its own reward) at the expense of playing in-character, or play more in-character and be compensated with
inspiration.