Tuesday 14 April 2015

Game Design #39: Reaction Moves, Reaction Fire

I've always been a staunch advocate of reactions in wargames. I mean, there's nothing worse than IGOUGO.  Your enemy can walk his troops right up to you to deliver a volley while your soldiers stand around like waxwork dummies, waiting their turn. It's unrealistic, and kinda boring.  Do you remember games where you'd walk off to get a drink while your opponent had their turn?  Standing around for 10 minutes as a passive spectator is boring, and frustrating.  I've learned when working with kids that hands on is best, and with "big" kids it's no different.  Reactions allows you to mess with your opponent's perfect plan, and make your soldiers respond to developing events with more realism and fluidity. They provide more decisions for you and thus the opportunity for tactics.

However reaction moves are not without flaws.  The extra interactions, whilst providing many decision points, can slow the game down dramatically.  The "reactions" can promote passive, "camping" gameplay and cut down on maneuver.  The extra rules add complexity.  (Tomorrow's War has situations where units are reacting to units who are reacting to other units... yes it hurts my head thinking about it too....)

Let's define some reaction types first.  The parameters of a reaction vary a lot, from simple "overwatch" mechanics in 40K to full blown unlimited reactions (Infinity) where what you do in your opponent's turn is often more important than what you do in your own. 

How often can you react?
Very Limited (many games)
Each unit gets a single reaction, and then that's it. A token is placed beside the unit to show it cannot react again.

Limited Common Pool (Lords & Servants)
Have activations in a single pool, and at the start of the turn you divide them up to use in either your own or your enemies' active phase.  I.e. you have 12 activations, and you plan to spend 7 of them in your active turn, and 5 reacting to your enemy in his.  This could also include common mechanics like "passing" your turn to acquire an overwatch token, which kinda falls into the "very limited" box.

Diminishing (Tomorrow's War)
Each unit can react multiple times, but it becomes less effective each time.  You track the # of reactions (say with a d6) and the amount of the reactions reduces firing or melee dice or similar - or decreases your chance of a reaction. I.e. lose a firepower dice each reaction.  Thus reactions are limited by initial firepower/combat stats.

Unlimited (Infinity)

You can react with every unit that can see any single enemy unit acting in LoS. As many times as needed. 

What triggers a reaction?
Actions only directed at the reacting unit. Sometimes a unit can only react if the shooting is directed at it, or the charge is made in its direction.

Movement/Shooting/Both (many games).  Sometimes any shooting triggers a reaction. Other times units can only react to moving units.  Often either moving or shooting triggers a reaction.

Anything (Infinity). If a model scratches its bottom, you can react to it. 

How Easily Can You React?
Automatically. If the unit triggers a reaction, you can carry it out.

Pass a dice roll.  You need to pass a target number on a dice roll to react. I.e. 2D6s vs Leadership.

Opposed Roll. (Infinity, Tomorrow's War)  You need to beat your opponent's roll, and a target number as well.

What range can you react to?
Set proximity (many games). I.e. any trigger within a set range - say 12" - allows a reaction. 

Unlimited/LoS (Infinity).  I.e. reactions are triggered by actions in line of sight, with theoretically unlimited range.

What Order do you React In?
Single vs Single - sequentially (many games).  A single unit acts, it resolves any reactions by enemies one-by-one. I.e. Unit A activates, it resolves any reactions by Unit X, then any reactions by Unit Y, then after that, Unit Z.

 Multiples vs single - simultaneously (Infinity). If a single unit acts, multiple units can target it and attack it simultaneously.    Unit A acts, and must simultaneously roll to beat Units X Y and Z.

 How severe is the reaction? 
Weakened (Infinity). Attributes are significantly restricted i.e. rate of fire is reduced from 3-4 shots to 1 shot only.

Diminishing (Tomorrow's War).  Reactions are initially full strength, then gradually decrease in potency.

Full Power (Lords & Servants). A reaction shot is every bit as good and potent as an ordinary shot. 

Other Considerations

Furthermore, the activation sequence can strongly effect reactions.  Many reaction-based systems operate with a modified IGOUGO - i.e. Side A moves his units one by one, then Side B reacts to each unit (cognizant on other factors such as limited number of reactions, etc).  There's an argument that alternate move (Chess style unit by unit activation) allows a kind of organic reaction anyway. For example, in Infinity you can activate a unit multiple times in your turn, so having unlimited, powerful reactions balances the game, preventing powerful units from "ramboing" around and soloing the enemy army single-handed.

Also, unit reactions (i.e. squads in a platoon level game) can be different than individual reactions (i.e. single based minis in 1:1 skirmish).

Finally, are reactions best suited to particular eras? i.e. WW2-modern-hard sci fi rules seem to most commonly have reaction systems - where use of cover and firepower is paramount and melee combat is deemphasized.   In this post I look at how a hard-core reaction system like Infinity may be integrally unsuited to medieval/fantasy because of the inherent gameplay style it encourages.

Also, are reactions better suited to particular "levels" of game? For example, I see reactions commonly used in platoon/skirmish games but less commonly at company/battalion/army level games (admittedly I don't play many of the latter). 

Reactions may be the new hotness, but are reactions always good?  Are they worth the potential speed/maneuver tradeoff?  Does it bring in enough involvement/decision points to justify added complexity?  When should we ditch them?  What is the best way to limit them? Limit the range, the amount of possible reactions, or maybe the triggers? 


  1. Maybe if moved/shoot/whatever style of actions were grouped together in 'tactics' or whatever, so that one unit can react to another unit's complex action with an option from a library of reactions?

  2. "(Infinity). If a model scratches its bottom, you can react to it."

    Love this line and so true. Have you had a chance to look at N3 yet?

    1. Sure. However it's simply so vast (250 pages!) - and my Infinity enthusiasm has waned as its just so fiddly to paint and assemble the minis (I have a lot of them...) I think I have the draft of Part 1 of a N3 review...

  3. I feel that there's a middle size where reactions work well.

    Very big games, it becomes a mess to track and very small ones, there's too few figures for it to ever really be needed.

  4. Using reactions as a Resource is an interesting mechanic. In skirmish games it feels a bit ... gamey (?) for lack of a better word. If Hank can react to being charged by an angry Thark, why can't Bob? Oh, because the reactions are all spent?

    However, as you go up in scale it can make more sense as the "commanders" attention has to be divided and he can;t actively order everyone to do everything at once.

    However, I have typically viewed Action/Reaction as a varient turn sequence as opposed to its own set of mechanics. For example, if I already am using Alternate Activation, do I really need a Action/Reaction mechanic as well? Wouldn't my turn to activate something give me the chance to "react" if I wanted to?

    Now I am re-thinking this thought process a bit. Thanks.

    1. "For example, if I already am using Alternate Activation, do I really need a Action/Reaction mechanic as well? Wouldn't my turn to activate something give me the chance to "react" if I wanted to?"

      Yes. As I said above, some activation types have some degree of built in reactions...

  5. I liked how the Starship Troopers Miniatures Game did reactions. there was a reaction distance (10", I think) and each faction had different possible reactions. The Mobile Infantry could either shoot, move, or standby (don't react). Honestly, I'd the like the reaction distance to be a little further, but with enough terrain, it should work out pretty well as is.

    1. So you're in favour of limiting reactions by range, and it's more the exact range you're dickering over.

      Once thing I have done before is divide reactions into TYPES of reaction:

      Aggressive (returning fire,counter-charging into contact)
      Defensive (taking cover, returning fire, retreating from contact)

      Units can take a defensive reaction anytime, but must test morale/leadership etc to make a offensive reaction; and if they ever fail a test, then no more offensive reactions that turn....

    2. Ideally I'd like an unlimited reaction distance, but have a limited number of reactions. I like your idea of aggressive & defensive reactions.

  6. An idea I've been mucking with:

    Each unit gets 1D6 actions. You roll the pool of dice at the beginning of the turn and assign the dice to figures as you activate.

    You can split those between actions and reactions as you see fit.

    If I want to react with a figure that hasn't gone yet, I can allocate any of the dice I have remaining to him/her

    1. It's pretty much identical to the system used in Lords & Servants, only you get a set pool of 3D6 actions, rather than based on the # of figures.

      Having such a spread as 1D6 (1-6) could be a bit luck-dependent. May I suggest

      1 = no action - bummer!
      2-5 = 1 action
      6 = 2 actions - bonus!

      Or something similar? That way you'd get a tighter, smaller spread, without zillions of unit tokens caused by rolling 8d6 or something... and it would simplify the math - simply sort them into 1s, 6s and everything else.

      It's something I'm fiddling with my Mordhiem-Infinity house rules. (I'm having fun trying to reconcile to diametrically opposed concepts).

      As unlimited reactions seem unfeasible, I'm exploring the middle ground as found in L&S.

    2. The rationale I went with is that since you can assign each of the dice, you can usually guarantee a high number of actions/reactions where it matters.
      It also creates the effect that if you need somebody to hold down a line of fire, you're going to need to spend one of your good dice on that guy, limiting you elsewhere.

      The biggest problem is that you need a bunch of dice (roll them all, set them side, then put them next to guys as you play). So kinda messy.

      I've been kicking around experimenting with "average dice" (233445) but I haven't decided it's worth the fuss yet.

    3. "The biggest problem is that you need a bunch of dice (roll them all, set them side, then put them next to guys as you play). So kinda messy."

      A token or dice per mini IS a bit much. I personally have no issues for a dice next to a unit, because the minis outnumber the dice and make it less prominent.

      "I've been kicking around experimenting with "average dice" (233445) but I haven't decided it's worth the fuss yet. "

      That's why I'm looking at things like the 1 and 5 method. Similar effect, no special dice needed. I stole the idea from the common system used for many on-combat actions in LOTR:SBG.

  7. I should add this is for a squad sized skirmish game but yeah.

    As you well know, I am fond of rolling 1's and 6's ;)

    1. Actually that's why I mentioned it. I thought "this might appeal to himI!"

  8. A random aside: I think skirmish games fall into 3 categories

    5-10 "RPG" category (Infinity, etc)
    10-20 "Mordhiem" category
    20-40 "LOTR" category (basically platoon level, but with individually moving minis)

    I think that the categories require a different focus/mechanics even though they are all "skirmish" per se. I've ran into problems when trying to scale up a Infinity-style game to include groups of troops (20-25); it makes the transition as poorly as 40K made the transition to a mass battle game (Armageddon -argh!)

  9. In noodling about after reading all of your game design articles, here's a system I'm playtesting for a Post Apoc skirmish game.

    Players get 2 Action Points per unit per turn. This allows each unit to Move 6" and Attack once each. Units can double Move for 2 AP, but trying to do a third move only moved the unit d6".

    For reactions, any unit that hasn't fired a single shot weapon (sniper rifle, crossbow) already this turn can spend 2 AP to fire at a target that leaves cover and interrupt their turn, which can result in Stunning the unit out in the open, for example.