Recently I tried borrowing 3.5e’s 5-Foot Step rule for 5e combat and so far I really like it. The way I introduced it is: if you move no more than 5 feet on your turn, you don’t provoke attacks of opportunity.
My motivation came from a couple of places.
First, the primary two characters I play are a Ranger and a Wizard, both of whom like to have some space between them and anything they might be attacking. But combat often gets into close quarters, where the choice between doing everything at disadvantage or taking the AoO—especially for the Wizard at lower levels—can be brutal.
Second, building on top of that, is that while running combat encounters, I found it too easy to slip into tactically good-enough spots and for movement to cease if a battle goes on long enough, as the threat of AoOs becomes more meaningful. Then it turns into hit point attrition and gets less interesting. To be clear, part of this is on me to learn to avoid—to balance combat so it doesn’t last too long, to ensure there are reasons for PCs and NPCS both to keep moving around, etc. But I’ve seen lots of people get stuck in the “well if I move at all I’m going to get hit so I’ll stay” aspect of 5e combat, which doesn’t help.
This would let the Wizard avoid disadvantage on attack rolls, but need to keep moving to do it, possibly giving up good positioning, without letting her actually getting a meaningful distance from a melee attacker.
In the first session I tried this out, offering it to the players as something I thought was worth trying but we didn’t have to keep, both PCs and NPCs got good use out of it. I do think it kept things a little more fluid and dynamic. One NPC did have a Sneak Attack feature, but they died early, so I didn’t really get to see the impact of taking away some of their AoOs.
There are probably some nuances that will be worth working out over time. Is it really per turn, or per round? (Could I move 5 feet, then Ready a Dash action?) Is it really “move 5 no more than feet” or “use no more than 5 feet of movement”? (Should standing up in place, then moving 5 feet away, still count? What if I’m crawling or climbing?) Are there feats like Athlete or Mobile that need to be updated? But so far, none of that’s come up, so it’s tough to say!
James DM 
I’m interested to know if this mechanic takes away too much from natural disengage abilities like the Rogue’s Cunning Action and Swashbuckler’s Fancy Footwork. Does the 5-foot step work better as part of a Feat instead of something that everyone just has?
I’m split on “standing up then moving 5 ft” because the spirit of the rule in 3.5 was “if you don’t use any other kind of movement,” but it also says you can take the 5′ step “if you move no actual distance in a round.” Does the z axis have any bearing on this movement?
LikeLike
Those are great questions! So far I don’t think so, but it may depend on the table. The Rogue is one of the people that’s taken advantage of it. There haven’t been all that many combat encounters yet so definitely still baking.
Totally agree on the spirit of the 3.5 rule, but I think taking the literal text in that case is tricky since there are a bunch of “move actions” that don’t involve moving, like drawing a weapon. Z-axis is definitely tricky, too, since it’s really tough to imagine that a medium creature over 5′ tall only controls the space of a 5′ cube. When would you normally provoke an AoO moving through the z-axis?
LikeLike
It’s all part of the “6 second turn” I think. Can you do the non-moving-movements AND still have the time to safely back up a bit? I believe so for most applications (I’m looking at you fighters that run 30′ then attack 4 times, use Action surge to attack 4 more times, then use bonus actions, all under 6 seconds).
I envision z-axis AoO moves being something akin to an enemy rising slowly due to a spell like levitation, or jumping down from a height, or climbing, swimming or flying. But those 3D maneuvers bring their own can of worms into the equation. Can you 5′ step while flying?
LikeLike
I agree. In my head, cinematically this kind of looks like Jackie Chan dodging an errant punch while stepping backwards, while full movement speed is more like turning around and losing sight of the attacker, giving them the opportunity. In that sense, I feel like it would be harder to dodge while crawling, and almost impossible while climbing.
The party in this campaign is about to hit level 5 so we’ll see what kind of chaos that brings and if it seems OP.
LikeLike