Quote Originally Posted by Greywander View Post
Lightning Reflexes
  • Increase your Dexterity score by 1, to a maximum of 20.
  • You may take one additional reaction each round.
  • Immediately before or after using a reaction, you may move up to 5 feet. This movement doesn’t provoke opportunity attacks.
  • You gain a +2 bonus to Dexterity saving throws. Whenever you use a reaction, this bonus decreases by 1, to a minimum of +0. At the start of each of your turns, the bonus resets to +2.

I kind of wanted to play around with the idea of giving out an additional reaction. Didn't want to give out too many, but even one additional reaction opens up some new options. Since the original Lightning Reflexes feat gave a bonus to reflex saves, I thought it might be nice to pay homage to that, as well. I'm not sure if there's too much going on in this feat. Maybe I should axe the extra movement. Thoughts?
Quote Originally Posted by Greywander View Post
Huh, I was thinking of axing the movement, but it does add something a bit more interesting. I should probably specify that it won't take you out of range of whatever triggered the reaction (e.g. if it was a reaction to getting hit, you still get hit even if you move out of range of the attack). Maybe I should remove the DEX bonus, turning it from a half feat to a full feat.

If I keep the bonus to DEX saves, I might only have it persist until you use a reaction, so it's either on or off, rather than trying to track how many reactions you've used. Or just make it a flat +1 or +2 that's always on.

Here's a revamped version:

Lightning Reflexes
  • You gain a +1 bonus to Dexterity saving throws.
  • You may take one additional reaction each round.
  • Immediately before or after using a reaction, you may move up to 5 feet. This movement doesn’t provoke opportunity attacks.

My other thought was to allow you to use a reaction to boost your DEX saves (instead of having an always-on DEX save bonus), like the War wizard's Arcane Deflection, but only for DEX saves. Here's what that might look like:

Lightning Reflexes
  • You may take one additional reaction each round.
  • Immediately before or after using a reaction, you may move up to 5 feet. This movement doesn’t provoke opportunity attacks.
  • When you fail a Dexterity saving throw, you may use your reaction to gain a +4 bonus to that saving throw.

(+4 is what Arcane Deflection gives, and it also only applies to just that one save, not to all saves. Ergo, it has to be strong enough to make it worth using.)
I think you'll be fine with either +1 to Dexterity and an additional reaction each round, or an additional reaction each round and some ability that boosts Dexterity saving throws somehow.

I do think the 5-foot movement thing is too fiddly.

You already have Resilient: Dexterity to get proficiency on Dexterity saving throws. Barbarians get advantage on Dexterity saving throws, so I wouldn't want to give advantage and make this a never-take feat for them, so something else.

I think letting you re-roll a failed Dexterity saving throw at the cost of a reaction would be fine. I would specify that you have to use the new roll (that is, you couldn't spend your second reaction if you still have it on the Dexterity saving throw if the reroll is bad).