Simultaneous Initiative (Adapted from Chainmail)

D&D's system of initiative was first introduced with AD&D, 1st Edition. Before that, many of the rules of combat were found in Chainmail, a set of rules for medieval miniature wargaming. The initiative system had evolved from the "Move/Counter Move" system of turn sequence found in those rules, but Chainmail also contained an alternative system for "Simultaneous Movement". It is from this that the following has been adapted for 5th Edition.

Simultaneous Initiative

1. When combat starts, every participant writes orders for the character or monster (or group of identical creatures) they control, including direction of movement and action to be taken.

2. Every participant takes up to one-half their movement and any actions they can take according to their written orders, checking for opportunity attacks and other reactions due to movement. Conflicting movement and actions are resolved with contested Dexterity checks. Participants who are targeted with a melee attack and haven’t already used their action may use their action to make a melee attack in return after the triggering attack. Then the remainder of movement and remaining actions are completed as ordered, with conflicts resolved and melee attacks returned as above.

3. Steps 1 and 2 are repeated for each round of combat.

I'm posting this for peer review. Let me know if there's anything I've overlooked or haven't explained well enough.

Thanks!

Interesting idea. I'll look into after dinner.

EDIT: Ok, after dinner.

The idea is definitely interesting, but since we just changed to a simpler system, I think it would slow things down too much in practice. Could you post an example, just so the idea is a bit clearer? Thanks!

I like this thing in certain games. Wouldn’t use it in D&D. Would work fine though I think.

Sorry premature post. Actual post coming soon to this thread.

Preliminary caveat: I have not looked at the rules for Chainmail.

Hriston said:

Simultaneous Initiative

1. When combat starts, every participant writes orders for the character or monster (or group of identical creatures) they control, including direction of movement and action to be taken.

2. Every participant takes up to one-half their movement and any actions they can take according to their written orders, checking for opportunity attacks and other reactions due to movement.

Click to expand...

Just to be sure, "actions" here includes bonus actions, correct?

May an order be conditional, thereby making whether "they can take" an action a matter of intent rather than physical possibility? E.g., "When Joe has moved 15 ft. north, I cast fireball." or "When/if the goblins come into range, I shoot my bow at the nearest one."

What about reactions due to actions (Shield, Counterspell, Hellish Rebuke, Riposte, etc.)?

Conflicting movement and actions are resolved with contested Dexterity checks.

Click to expand...

Movement and actions can 'conflict' in several different ways that, potentially, one might want to resolve differently. This description is ok as a summary, but, for instance, as a player I'd want to know a lot more about how you propose to handle various cases. I have a bunch of examples in mind, but I am pressed for time; will return to this tomorrow.

Participants who are targeted with a melee attack and haven’t already used their action may use their action to make a melee attack in return after the triggering attack.

Click to expand...

So it would seem that sometimes not having used your action will be an advantage. Is there a 'delay' option (a generalization of the conditional action declarations alluded to above)?

Then the remainder of movement and remaining actions are completed as ordered, with conflicts resolved and melee attacks returned as above.

3. Steps 1 and 2 are repeated for each round of combat.

I'm posting this for peer review. Let me know if there's anything I've overlooked or haven't explained well enough.

Thanks!

Click to expand...

I have been experimenting with simultaneous action resolution for about the last year. In some ways I like it better than the standard procedure, but it definitely had challenges and downsides that I did not foresee. The dividing the round in half idea is an interesting twist. Off the top of my head, I'd guess that it would reduce the frequency of, but not eliminate the challenges/downsides that I have encountered. More details tomorrow.

Hriston said:

I'm posting this for peer review.

Click to expand...

Have you playtested it? If so, let us know how it worked.

I don't like the sound of everyone writing orders for every character every turn - I'd think that would slow things down even more. I'd rather have a phased side-based approach as in Moldvay B/X.

Feels like a half-turn or speed-2 turn based system, ala HERO if every charscter had speed-2. Seen this kind of thing in more than z few places, usually with a lot more robustness in terms of character-based differentiation and action/sub-action details.

Without that added robustness and a lot of playtesting, a quick slap-patch into the DnD 5e framework will prove almost sure yo be a yon of moment-to-moment breaks.

And you still need an order to resolve because there are going to be a lot of if-then kind of situations or a lot of blindly stupid situations - walk into pit that wasnt there or any number of more complex things.

Honestly, seems like a lot of work to just sub-divide turns and still wind up with actor-based initiative system. Only thing it adds is more blind or low-information choices for a system where minute differences can be critical.

This kind of thing tends to work best at bigger scale system, where you are managing groups not units, where the granularity is dialed to "sorta-close-enough" and where low-information choices are common - not single-unit systems where the granularity is dialed to the point of a single hp or 5' square can be massive. (Which is why i can see it put in as a **variant** for a single unit game derived down from larger scale miniatures scale games - not their first choice.)

Without a ton more meat on the bones and a lot of the transformations of rules resolved, hard to assess further.

But in general, having played many "sequential resolution" systems, they dont tend to add more to the experience than complexity and a different host of "doesnt quite work rights" to the game play. More a false precision.

Here's an example adapted from the 1st Ed. PHB, p 105:

A party of 5 characters -- a wizard, a cleric, a rogue, a human fighter, and a dwarf fighter surprise an illusionist with 6 orcs. The opponents are 30’ distant.

Orders for Round 1
wizard: cast sleep on the location of the opponent group
cleric: cast silence on the illusionist's location
rogue: move into the area of darkness to the rear of the party and hide
human fighter: fire an arrow at the illusionist
dwarf fighter: throw a handaxe at the illusionist
illusionist: surprised
orcs (6): surprised

Resolution of Round 1: The rogue takes half of his movement at which point he is heavily obscured by the darkness and hides while the fighters make their attacks which both hit the illusionist. Upon seeing the casters casting their spells, the illusionist can cast counterspell if his surprise has worn off before one or both spells are cast. He wins a Dexterity contest against the wizard and interrupts him, causing his spell to fail. Meanwhile, the cleric successfully casts his spell, and the rogue finishes his remaining movement.

Orders for Round 2
wizard: ready burning hands to cast if the orcs come within 15’
cleric: ready to attack the orcs with a melee weapon if they come within 5'
rogue: dash through the darkness around the edge of the room towards the illusionist
human fighter: ready to attack the orcs with a melee weapon if they come within 5'
dwarf fighter: ready to attack the orcs with a melee weapon if they come within 5'
illusionist: cast prismatic spray
orcs (6): throw javelins at the party and rush into melee range with them

Resolution of Round 2: The rogue takes the Dash action and moves stealthily 30' through the darkness. The orcs throw their javelins at the party and close to melee range (Aggressive). Javelins hit the wizard and the two fighters, and the wizard fails his Constitution save and loses concentration on his readied spell. The cleric and the two fighters attack the orcs, killing one and wounding another. Five orcs remain, one each in front of the cleric and two fighters, and two in front of the wizard. Meanwhile, the magical silence prevents the illusionist from providing the verbal component of his spell, so he's unable to cast it. Then the rogue completes the rest of his movement.

Orders for Round 3
wizard: cast acid splash on the two adjacent orcs
cleric: attack the adjacent orc with a melee weapon
rogue: sneak up on the illusionist from behind and stab him with a sword
human fighter: attack the adjacent orc with a melee weapon
dwarf fighter: attack the adjacent orc with a melee weapon
illusionist: cast hypnotic pattern on the party's location
orcs (5 remaining): grapple adjacent party members

Resolution of Round 3: The rogue cannot be heard as he sneaks up behind the illusionist, who is busy casting his spell. He stabs the illusionist in the back, killing him and immediately breaking his concentration on his spell as it is cast. One of the orcs facing the wizard makes his Dexterity save to avoid the wizard's acid bubble, and one does not and takes acid damage. Both orcs are successful in grappling the wizard. Both fighters' attacks miss their targets, and both are grappled. The cleric successfully resists being grappled and kills the orc trying to grapple him.

Orders for Round 4
wizard: try to escape from being grappled
cleric: attack the orcs grappling the wizard
rogue: move to the orcs grappling the nearest fighter and attack
human fighter: try to escape from being grappled
dwarf fighter: try to escape from being grappled
illusionist: dead
orcs (4 remaining): attack grappled characters with daggers

Resolution of Round 4: The cleric kills one of the orcs grappling the wizard, while the rogue uses the first half of his movement coming to one of the fighter's aid. The grappled characters are unsuccessful in escaping. The three remaining orcs check morale, however. If they succeed on their Wisdom save, they carry out their attacks. If not, they release the grappled characters and run away.

Is there a problem with the existing rules you're trying to solve with this? At first glance, it looks like a huge slowdown in play for no real payoff that I can discern. Personally, I prefer the simplicity of the current system, and I think slowing play is a huge price to pay, so if there's no commensurate improvement in the game, it wouldn't be worth it to me.

Harzel said:

Preliminary caveat: I have not looked at the rules for Chainmail.

Click to expand...

A lot that became and is still part of D&D, including the initiative system, has its roots in Chainmail. The purpose of this thought experiment, rather than an attempt to fix anything, is to imagine how “simultaneous movement” could work if it was brought forward into the current edition in the same way that the “move/countermove” system was.

Harzel said:

Just to be sure, "actions" here includes bonus actions, correct?

Click to expand...

Yes, as in the example when the orcs use the bonus action given to them by the Aggressive trait.

Harzel said:

May an order be conditional, thereby making whether "they can take" an action a matter of intent rather than physical possibility? E.g., "When Joe has moved 15 ft. north, I cast fireball." or "When/if the goblins come into range, I shoot my bow at the nearest one."

Click to expand...

Yes, I’d consider this a use of the Ready action, though, with the limitations that come with that.

Harzel said:

What about reactions due to actions (Shield, Counterspell, Hellish Rebuke, Riposte, etc.)?

Click to expand...

Reactions would come up in the process of resolution rather than during the “action-declaration” phase, as in the illusionist’s casting of counterspell in the example.

Harzel said:

Movement and actions can 'conflict' in several different ways that, potentially, one might want to resolve differently. This description is ok as a summary, but, for instance, as a player I'd want to know a lot more about how you propose to handle various cases. I have a bunch of examples in mind, but I am pressed for time; will return to this tomorrow.

Click to expand...

I’d like to hear these. What I have in mind is if the resolutions of two actions are incompatible, then a Dexterity check decides which one happens. In my example, this happened when either the illusionist could cast counterspell, because his surprise had worn off before the wizard cast his spell, or he couldn’t cast counterspell, because he was still surprised. Those two resolutions to the action of the wizard casting his spell couldn't both be true, so the dice decide which of the two is actually what happens .

Harzel said:

So it would seem that sometimes not having used your action will be an advantage. Is there a 'delay' option (a generalization of the conditional action declarations alluded to above)?

Click to expand...

As above, it would be the Ready action, which I guess looks a little funny in a system like this where you don't have an initiative, but it operates the same way. Instead of taking your action simultaneously with everyone's movement and action during one of the two movement phases, you take it as a reaction in response to a perceivable trigger.

Harzel said:

I have been experimenting with simultaneous action resolution for about the last year. In some ways I like it better than the standard procedure, but it definitely had challenges and downsides that I did not foresee. The dividing the round in half idea is an interesting twist. Off the top of my head, I'd guess that it would reduce the frequency of, but not eliminate the challenges/downsides that I have encountered. More details tomorrow.

Click to expand...

Great! I look forward to hearing about it!