This is how we’ve been doing initiative for the last few months. It’s fast and it gives a varied result with a lot of back & forth instead of first all on one side go, then all on the other side goes. Best of all, your parry is immediately followed-up by your own attack.
The light first strike is negated if the place is already lit, or if no-one or both have light. In that case, home turf goes first (so monsters, in a dungeon, or player characters, if defending their home). 5e has special abilities like “Rakish Audacity” and the like that also can grant first strike.
The order can get changed over the course of the battle as players leave and join groups. That can get a li’l tricky to keep track of. Make sure everyone still get the correct amount of actions for each round.
Let’s say there are these three groups:
and Mike and Wendy are hanging in the back rank, blasting.
Here we’d have Terry’s skeleton go first, then Terry, then Cecilia, then Cecilia’s skeleton, then Felix, then that skeleton, then Doris, then the wight, then Mike and Wendy, and then back around in a seamless loop.
Let me break down that same example.
A skeleton slashes at Terry, who parries the attack (by having high AC or by paying HP).
Terry then follows up that parry by a slash back at the skeleton.
We go over to Cecilia’s group. Thanks to her light keeping the skeleton at bay, she gets to go first, and she swipes at the skeleton with her dagger. The skeleton pays some HP to step away just in time, and then slashes back with a shortsword, which Cecilia narrowly ducks under.
Then over at Felix & Doris, they also have first strike because of Felix’s lantern. He slams his mace at a skeleton, who is barely keeping it together (down to three hitpoints!), but follows-up with a strike back at Felix (so follow-up overrides first strike). Then Doris finishes off that skeleton with her axe. The wight is left in that group and tries to drain the light out of Felix and slash at Doris with a sword.
Mike and Wendy are hanging back, and get to go next, and after them we’re back at the skeleton by Terry.
A huge advantage to not having to roll for initiative is that it really blends up exploration and fighting more seamlessly. It’s not “now we’re in the fighting minigame”, it’s mixed up with talking, pulling levers or whatever. Chopping your sword is an action like any other action.
Y’all know I hate movie terms when DMing (if you love movies so much then make one, while we’re down in the mud looking to pry the rings of the hands of the shambling bones), but even I’ll grant that no movie editor would be proud of a fight where we’d see Bruce sock a goon, then Dick pow another goon, then Bruce get socked by the first goon and Dick get powed by the second goon. That’d be confusing and disjointed. That’s why the follow-up attacks are so great. Being organized by group is also good because it enables nifty team-ups and fastball specials.
This system is a li’l bit complicated but it’s been working so great. And it cuts down on the number of steam rolls and ensures more of a back and forth. We’ve used it for more than fifty sessions and I love it. Next thing I want to try is to break up multiattacks so there’s even more of a back-and-forth within a group. I deliberately didn’t do that, especially since many attack attempts just miss anyway, and it’s a lot harder to keep track of: here I just need to go through all the groups one by one and even so we sometimes miss someone—just imagine, then, having to keep track of individual actions. But ABT—always be testing—maybe it’s gonna be epic, and make even low-level monsters feel legendary and make the reverse swarm solo designs feel less out of place.
When people wanna do things out of order, don’t shut that down, but just do the “When you…” key phrase. “While Wendy is starting that spell, Terry, a skeleton is slashing at you with a shamshir, what do you do?” Keeping the fight actions diegetic takes a li’l bit of extra time but can also make things clearer or more visceral.