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In working on a new game system, I'm looking for any relatively-balanced system that uses initiative in a specific way. I'm just looking for a reference point and inspiration, or if anyone else has any better ideas...

The idea is to give players the ability to spend part of their initiative or actions on the ability to interrupt or respond. The trick is, this needs to scale up as the character levels. The systems I have found so far that allow for this, like Shadowrun, do not give the characters the ability to increase the amount of actions they get or the frequency with which they can respond as the character levels; it's based on magic or gear. I'm looking for something inherent in the system and the characters.

No limitations on how simple this needs to be; I'm looking to have this calculated electronically, so even if the solution is something like (roll Xd6 where X is the characters level divided by 2 and add their speed stat to each roll except on Tuesdays when you should instead add speed + intelligence...) then that's fine.

Thank you!

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5 Answers 5

After taking a minute to spin through all of the initiative systems that immediately jump to mind, I think 7th Sea or Scion might be the closest fits to the sort of thing you're looking for.

7th Sea

Initiative in 7th Sea relies on a repeating track referred to as a (Combat) Round. Each round breaks down into ten phases, counting up from 1 to 10. By default, any given participant rolls a number of d10 equal to one of their traits and their actions occur on the Phase(s) corresponding to the dice. This can be as few as 1 and as many as 7, although typically characters will have two or three actions in a round at creation. Ties are broken by totaling these dice and getting an actual Initiative total. Barring any special abilities or rules, they can hold exactly one of these actions if it is unused by the end of its marked phase (thus having two actions on the same phase means one will be used or discarded). At the start of a new round a held action is lost. Attacks can only be done with a current (die showing which phase the round is on) action or a held one. An "interrupt" action allows a character to spend any two of their action dice to go right now for anything but an attack, which is most often utilized for making a defensive roll.


  1. Very optimized for multiple actions in a round
  2. Slower characters don't necessarily act last, just less
  3. Faster characters don't invest heavily just to go first by a wide margin and fall flat
  4. Concise breakdown of what can be done in an action/round when time counts


  1. More people generally means slower combat than single action/turn mechanics
  2. Everyone needs to keep track of more data (with the GM practically having a spreadsheet)


The most interesting idea behind the combat mechanic in Scion is that it takes place on a wheel separated like a pie into 8 parts called "ticks", numbered 0 to 7. Everyone rolls initiative, which is called "Join Battle". You take the highest result of all participants and start whomever has that number at 0. Follow the ticks around the wheel for subsequent Join Battle rolls, i.e. if the best roll is a 7 and the next best is a 3, then the character with 7 starts at 0, and the one with 3 starts at 4. Every action has a Speed associated with it, or the number of ticks it takes to complete. For weapons it's the cooldown before it can be used again but for other actions, it is meant for the character to be completely ready. Almost every action takes away from the character's ability to defend themselves and until they fully serve the time until their next official action, this penalty to their Defensive Value (DV) stays. "Holding" and action, or "Guarding" is a no penalty, 3 tick action with no actual results thus interrupting it has no downside. Not every action can be interrupted though to prevent insane attack rates.

Alpha starts at tick 0, Beta starts at tick 3. Alpha starts a Dash (3 speed, -2 DV). At tick 2 he stops running because he is now in range to swing his sword (4 speed, -1 DV). Right now he has a -3 to his DV until tick 7. Beta takes advantage of this to do a heavy unarmed attack (speed 5, -2 DV) and now doesn't act until tick 0 comes around again


  1. Allows for strategic action planning
  2. Faster characters/actions aren't treated the same as more sluggish ones
  3. Finely timed actions


  1. Slows down exponentially with more participants (and the game encourages followers/lackeys)
  2. Lots of desk checking since a characters are constantly bargaining their DV
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If I understand the question, good luck, because

The Palladium Combat System Is Similar

In Rifts and other games using Palladium Books' system, characters have what the game calls attacks per melee but are, in reality, actions per melee round, which vary--depending on character options and level--between 2 and in the low hundreds, depending on how thoroughly the system's been abused.

When combat begins, initiative is rolled on 1d20. The character with the highest initiative result takes his action, then the next highest takes his, and so on until every participant's taken 1 action and then the process begins again, from highest to lowest, for those who still have actions, until no characters have actions remaining. When a character's exhausted his actions, he can take no more. If other characters can still take actions while one or more characters can't, the other characters continue to take them in initiative order. While this system can leave one especially active character with a big pile of actions at the end of the melee round, it usually doesn't (see below). When all participants have taken all their actions, initiative is rolled again and the next round begins.

When a character takes an action the action's target can respond to that action by borrowing against his future actions to do so. Others can also respond at the GM's discretion, and whether the borrowed future action is the borrower's next action or the borrower's concluding action is the subject of heated debate.

The character who initiated the action will always take his action, but the target's action may change his result. If the target successfully dodges, the target won't be hit, for example. The list of responses the target can make is limited (usually only a dodge or parry), but contrary to many systems, the borrowed action can be an actual--if simultaneous--attack. Thus two characters can trade gunfire when the acting character shoots at a foe who has a readied gun. This often leads to one-sided slugfests involving terrific collateral damage, cratered wastelands, and destroyed million-credit mecha.

Under most interpretations of the rules, a character can borrow from his future actions until he exhausts his actions this round and then continue borrowing future actions from the next and successive rounds. This can lead to cases where a single character has borrowed so many future actions that he can't do anything but respond to others' actions for, like, a month.

Does It Work?

If the system were more precise and scaled appropriately, it'd be workable if confusing and time-consuming. It's very nearly indefensible as written, however, as its ambiguity necessitates a vast amount of GM adjudication (moving during combat, for example, goes nearly unmentioned).

Were a hard, static number of actions per round given to characters and these became more numerous as the characters gained experience, and a definitive action list were created to quantify the proceedings, the combat system's spine could remain intact. High-level characters would steamroll low-level foes, dodging their attacks and filling them full of lead when the low-level dudes were foolish enough to take arms against them. There's a solid combat system in there, but there's a lot of work until it's realized.

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This sounds a lot like "Passes" in Shadowrun –  CatLord Apr 1 at 2:35
"Indefensible" meshes nicely with my memory of Rifts, a game that ended up being as awful in practice as it sounded awesome in principle. –  gomad Apr 1 at 21:32
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Feng Shui

This system sounds like something you're looking for. Here's a rough summary, as I remember it:

At the beginning of each round, each character rolls a die and adds it to their speed; The result becomes their initiative. Starting at the highest possible initiative value and counting down, characters perform actions. The twist is that rather than just acting once each round, characters may act many times - as every action a character takes reduces their initiative by a specific amount (usually 3 points), and the character will then get to act again on their new initiative. For example, a character who acts on initiative shot 11 will most likely get to act again on initiative shots 8, 5 and 2 that same round.

On top of this, it is possible for characters to spend points of their initiative to react to certain events (most commonly by attempting to actively dodge an incoming attack, at a cost of 1 point of initiative).

This does sound kind of like what you want. Of course, you'll have to customise the initiative-generation technique and point costs of actions and reactions to suit your game, but that shouldn't be too difficult.

There are a couple of drawbacks to this method. One is that it conflates reaction speed with general speed of action; Another is that characters with high speed (and thus initiative) will often get to act multiple times before slower characters can get a move in. Whether or not these are problems for you will depend on the details of your game system.

EDIT: Ah, I just realised I forgot to mention that Feng Shui doesn't permit you to perform any more actions or reactions in a round once your initiative reaches 0 or below. This is kind of important, since the defence bonus it provides is significant; It would otherwise be feasible for characters to keep their heightened active defence "always on."

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Hero System

The Hero System divides each turn into 12 segments. Characters have a Speed rating that determines how many times they can act each turn, spread evenly through the segments (thus faster characters get more actions, but not all at once). You can hold actions until later, and you can borrow against future actions for certain maneuvers (generally defensive options).

Normal humans generally have 1–3 Speed; characters with more than 8 Speed are very rare. You can increase Speed with experience, magic, or gear – although the way Hero works, those are often just different ways of looking at the same thing.

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EABA2 seems to be a fit.

The core dice mechanic is roll and keep, rolling a number of d6 equal to skill + stat and keeping the best 3. You can take as many actions in a round as you like, but each major action (attacking, etc.) reduces all future rolls in the round by a die and minor actions (reacting, defending) give -1 to later rolls in the round (with a -3 penalty being equivalent to losing a die, so you'd roll 3d6-1 rather than 5d6-7).

The only limit on how many actions you can take in a round is how big of penalties you can take and still have a chance of success, which naturally increases as your character's skills improve.

In actual play, it does end up being a very heavy, fiddly system (and I have a high tolerance for rules-heavy systems), but the core concepts are simple and elegant enough that it should be very well-suited to automation.


Initiative is handled as a secret bidding process. Each player gets to choose the initiative number on which they take their first action in a turn, up to a maximum of their Agility stat, with additional actions coming each 3 "initiative points" after that. So, for instance, you could bid 6 for initiative and you would act on 6, 3, 0, -3, -6, etc. until you decide that you're done for the turn.

So why doesn't everyone just bid their full Agility every round? Because your initiative bid is a penalty to all skill rolls for the round. Bid 6 for initiative, and you roll 2 fewer dice on all your skills. So initiative becomes an additional layer of tactics as you weigh whether you want to act quickly, but suffer for being rushed, or take your time and maximize effectiveness, but take the risk that you might be taken out before you get to act. And, as with additional actions, characters with higher skill ratings are able to absorb more penalties, allowing them to bid higher for initiative while still remaining effective.

Interrupt actions tie into an additional wrinkle in the system, called "turn mod". EABA2 uses variable-length combat rounds and longer rounds give a certain amount of "turn mod" based on the length of the round. Turn mod may be applied as a bonus to any skill roll in the round, representing that you're spending additional time on that action. If you need to take a "desperation action" to react defensively to a threat to your life, you can take an action which could be completed in a second or less (e.g., diving for cover) by giving up as much of your own turn mod as the turn mod being used against you. e.g., If the current round is 4 seconds long (turn mod +4) and a sniper spends 2 of his turn mod to fire an aimed shot at you, then you can give up 2 of your turn mod to take cover before he shoots as an interrupt action, assuming you have at least 2 turn mod left.

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