Simultaneous Initiative (Adapted from Chainmail)

[Lanefan]

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.

With or without consultation with the other players/PCs?

If you don't allow consultation and have orders written mostly in secret this could work quite well and nicely provide a fog-of-war effect. Allowing them to consult before each round gives them far too much of an advantage of synergy IMO.

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.

If after the first half of someone's actions etc. gets resolved the second half no longer makes sense, can the second half be changed or is the PC committed no matter what?

This has always been my issue with pre-declararion of actions; that sometimes a pre-declared action doesn't make sense by the time the PC gets to do it. Example: I declare that my archer this round is going to move to point X and then take a shot at opponent Y. First half: I move to point X and get ready to shoot, but meanwhile someone else slays opponent Y. My intended shot for the second half is now pointless unless I'm allowed to retarget.

The issue would go away here were you to make each "half" its own new round.

 

[Lanefan]

The point of simultaneous initiative is to account for the fact that you dont know what your opponents are going to do and thus cant make a tactical move after getting full information. It may lead to more cautions play but how many players really do that?

This.

You also don't necessarily know what your fellow party members are going to do.

 

[Composer99]

So the halfling rogue pushes the Goliath barbarian out of the way? I think most folks are going to have issue with that. A single way of resolving such conflicts just isn't going to work. You wil need a complex system of resolution with lots of rulings or edge cases.

That doesn't seem right: the conflicts to which the OP is referring to are conflicts of ordering - which actions happen in what order, when it matters - not all contests.

 

[John R Davis]

The Bolt Action wargame has a nice order/initiative system, sure that could be adapted to an RPG. Not quite simultaneous though

 

[Shiroiken]

As a caveat brainstorm, this would likely make combat harder for PCs since they are often outnumbered. Foes who would normally die might get their dying shot in, and this favors the enemy.

Pretty much all simultaneous initiative system favor the enemy. The individual turns allows the players to react much better, and PCs are much more flexible than most monsters. Tactics and encounter building would definitely have to be altered, with fewer enemies and better planning by PCs.

 

[clearstream]

If you don't allow consultation and have orders written mostly in secret this could work quite well and nicely provide a fog-of-war effect. Allowing them to consult before each round gives them far too much of an advantage of synergy IMO.

If after the first half of someone's actions etc. gets resolved the second half no longer makes sense, can the second half be changed or is the PC committed no matter what?

I assume communication and tells that aren't narrated, but that characters in-world are conscious of. So I don't share the concern for information-hiding that perhaps motivates the OP.

This has always been my issue with pre-declararion of actions; that sometimes a pre-declared action doesn't make sense by the time the PC gets to do it. Example: I declare that my archer this round is going to move to point X and then take a shot at opponent Y. First half: I move to point X and get ready to shoot, but meanwhile someone else slays opponent Y. My intended shot for the second half is now pointless unless I'm allowed to retarget.

I agree with that! From experience, it can feel bad in play and you end up allowing players to adjust their actions. Maybe the thing to do is design some class features around that? (The bug becomes a feature.)

 

[Musing Mage]

Simultaneous results are easy to adjudicate in older editions, and they generally have that covered in the rules. 1e for instance simply has you resolve all actions regardless of the outcomes... so it's possible to skewer one another and both die for instance.

I don't think adjudicating them in 5e would be that difficult to implement, and given the d20 roll for initiative, it wouldn't be too common an occurrence. If two characters do end up with the same result, then their actions simply happen at the same time - which if they are aiming at one another is where the simultaneous result will need to be adjudicated. In this case, I'd say as DM make your 'declaration' as to the creature's action secretly, and then let the player resolve their action first before revealing the enemy action. Both actions are considered to have happened at the same time and are resolved together.

 

[LordEntrails]

That doesn't seem right: the conflicts to which the OP is referring to are conflicts of ordering - which actions happen in what order, when it matters - not all contests.

My understanding of the OP is that movement is simultaneous. So if a hafling and a goliath both write orders/intention to move into the same square, their is a conflict. Which the OP rules says is resolved by a dexterity contest. Which, as I say, doesn't lend itself to being dexterity dependent.

Or, how else would one use the rules laid out in the OP (or have they been modified since?) to determine who ends up in a square? (Or other conflicts of commands one can imagine).

 

[Composer99]

My understanding of the OP is that movement is simultaneous. So if a hafling and a goliath both write orders/intention to move into the same square, their is a conflict. Which the OP rules says is resolved by a dexterity contest. Which, as I say, doesn't lend itself to being dexterity dependent.

Or, how else would one use the rules laid out in the OP (or have they been modified since?) to determine who ends up in a square? (Or other conflicts of commands one can imagine).

The Dexterity contest determines determines the order in which conflicting actions occur. If the halfling wins the Dexterity contest, it means they got to the space first, not that they shoved the goliath out of the way.

Now, this does raise questions - what happens next? Can the goliath change their original written orders based on this event, and so either move to a different space or attempt to shove the halfling out of the way (now resorting to the contest described in the shove special attack)? Or are they stuck with what they wrote? These probably need to be answered to some degree of satisfaction for the system to be robust.

But, at least IMO, there's no ambiguity about how the Dexterity contests as described in the OP are intended to resolve conflicting orders.

 

[LordEntrails]

The Dexterity contest determines determines the order in which conflicting actions occur. If the halfling wins the Dexterity contest, it means they got to the space first, not that they shoved the goliath out of the way.

Now, this does raise questions - what happens next? Can the goliath change their original written orders based on this event, and so either move to a different space or attempt to shove the halfling out of the way (now resorting to the contest described in the shove special attack)? Or are they stuck with what they wrote? These probably need to be answered to some degree of satisfaction for the system to be robust.

But, at least IMO, there's no ambiguity about how the Dexterity contests as described in the OP are intended to resolve conflicting orders.

Ok, I get it. So now the system becomes even slower (or at least imo very flawed if you don't solve this type of conflict).

As I said originally, this type of system can be great for a group of wargamers who want fog of war and tactical realism. They are ok with single turns taking an hour (I've played wargames where single turns take hours, I'm looking at you NATO!) But I don't think most roleplayers want such a thing. If a table does, great, go for it.

I don't want to discourage the discussion here, so I should just bow out and let those who want such a system go develop one. I would just warn any DM taking such a route to make sure their players want to play such a game.