Review: Chain Reaction 3.0 and Swordplay

Posted: 27 April 2011 in Reviews

These are my go-to rules for skirmish wargaming, and as you’ve probably noticed, a lot of this blog deals with them and other rules from the THW stable. So you’ll probably guess my conclusion; do yourself a favour and grab the freebies right away. You’ll either hate it, or start collecting the genre-specific rules.

Two things make THW rules unique; first, their approach to the game turn; second, their unparalleled support for same-side or solitaire play. I’ll tackle those first, then move into the individual games.


One of the problems for a tabletop wargame is how to simulate the chaotic ebb and flow of combat with a clear and understandable turn sequence. Mainstream wargaming has historically tried several approaches to the problem.

The most popular, since the days of HG Wells’ Little Wars, is that of alternating turns. Side A moves, shoots, and engages in melee; then side B does likewise. The problem with this is that a fast-moving army (Blood Angels, I’m lookin’ at you) can move into charge range unopposed, shoot you to pieces, and then charge home and finish your troops off while they’re standing around like lemons waiting for your turn. Some games attempted to deal with this by introducing a reaction phase, when side B could react to side A’s moves partway through side A’s turn.

The second most popular is simultaneous movement to strict written orders. The problem with this is you spend too much time scribbling orders, and not enough time actually playing. This rose to prominence in the 1960s and 1970s and can still be found in some games today.

I noticed in the 1990s and 2000s that some rules sets were starting to use playing cards; each unit drew a card, and was then able to move, shoot and melee in the order the cards dictated. I haven’t really played many of these, so can’t really comment – I’ve used it in Savage Worlds, but typically there are only half-a-dozen figures per side in RPGs.

In a THW game, most figures move, shoot and melee based on reaction tests; some of them won’t do anything at all, and as you move each of those that are active in turn, it spins off its own subturn, of variable length, in which its actions and reactions are driven by reaction tests. You can’t rely on your troops, apart from one or two key figures, doing what you want; and you can’t predict what the opposition will do, or when. I can best summarise this with a quote from the rules themselves:

Our figures start on opposite sides of a building and are out of sight of each other.

  • I activate and I move first.
  • I move my figure around the corner and your figure can see me.
  • You take an In Sight Reaction test.
  • Maybe you shoot at me.
  • Maybe you shoot at me but rush your shot.
  • Maybe you don’t shoot at me.
  • If you shoot me either you hit me or miss.
  • If you hit me I see how bad the damage is.
  • Maybe I’m only stunned.
  • Or maybe I’m knocked out of the fight or worse.
  • But if you miss I take a Received Fire Reaction Test.
  • Maybe I shoot you.
  • Maybe I duck back for cover.
  • Or maybe I run away.
  • We continue to fire back and forth at each other until either one of us gets hit, runs out of ammo, ducks back behind cover, or runs away.
  • When all the reactions are finished it’s your turn.

The big thing is you get to react to what I do just like in real life.


As so many of the figures on the table move and fight according to reaction tests, it’s entirely feasible to have one side with no players on it at all. If playing solitaire, you take one side and the rules act as an "AI" to command the other; if playing with friends, you can very easily all be on the same side. I love this, because it means when my son and I play together, we can play co-operatively rather than against each other.

Don’t be fooled though; the non-player reaction tests are basic, but generate quite complex and credible situations. The game ruthlessly punishes poor tactics. I do not often beat it, and my son (who is a much better tactician than I am) gets a good run for his money.


This is the latest incarnation of the Chain Reaction rules, a 42-page Acrobat PDF file, and is available free to download from Two Hour Wargames. The primary mechanical differences from earlier editions are a more complex approach to melee, and expanded reaction tables.

  • Prologue and Introduction: 2 pages. These explain the history and core concepts of the game, including the difference between traditional and THW turn sequences.
  • Equipment Required: 1.5 pages. Dice (d6 only), figures or counters, something to represent buildings, and a playing surface – 3′ x 3′ and up. THW doesn’t mind what figures you use, if any; the rules are neutral as regards miniature suppliers.
  • Defining Characters: 2 pages. As befits a skirmish game, the figures can be treated as individual characters. Each must have a Rep; this ranges from 1 to 6 or more, the higher the better, and the average soldier has Rep 4. In addition, figures may (but need not) have other attributes which make them better or worse at various types of tests. The key differentiator is whether the figure is a Star (one that will usually obey the player’s intentions) or a Grunt (an NPC who does what the dice tell him).
  • Getting Started: 1.5 pages. How to recruit your force, and army lists. You can play what you feel like, or use random tables to determine what your Star commands. Army lists are provided for military, police, insurgent or gang forces – each of these uses a different table for reaction tests, reflecting their motivations and training. (In earlier versions, there were fewer variants of these tables.)
  • Organising Your Force: 1 page. How to divide your figures into groups, how to allocate leaders and what benefits they offer, how leaders are replaced if they fall in battle.
  • Rules of War: 11 pages. This is the mechanical meat of the game; how to determine who acts when in a turn, what actions you can order your figures to undertake, movement, reaction tests, shooting, melee, wounds and recovering wounded, and challenges – this last is a neat mechanic for resolving any weird or unusual ideas the players have. Want to hotwire a car? Want to jump from roof to roof? Want to defuse a bomb? They are all challenges.
  • Fighting the Battle: 2 pages. How to set up terrain for urban or rural games.
  • Vehicles: 2.5 pages. Entering and leaving them, driving them, ramming them into each other.
  • The Battles: 3.5 pages. A basic patrol scenario, including Probable Enemy Forces. PEFs are a mechanism for solo or same side play; a number are placed on the table at the start of the game, and move about according to reaction tests. Each of them may, or may not be, an enemy force – to find out, you have to get a figure close enough to see it.
  • Reaction Tables and other quick reference sheets. 4 pages. After a couple of games, you only need these sheets to play. After a couple of dozen games, you probably won’t need these either.

Straight off the printer, you could play any 20th century or early 21st century conflict of your choice.


This is the gun-free version of Chain Reaction, intended for ancient, mediaeval, and fantasy skirmishes. It is likewise free to download from the THW website. It’s extremely close to CR3 in mechanics and other content, so I’ll only talk here about the differences.

  • No guns. Unless you count the arquebus. There are thrown weapons, bows and crossbows.
  • Shields. These are added, as they are much more commonplace on mediaeval battlefields.
  • Army lists. These are replaced with more appropriate ones; Barbarians (ancient Germans), Empire (Rome), Eastern Empire (Fatimid Egypt etc), Feudal (mediaeval European), Nomad (Huns), Northmen (Vikings), Dwarves, Elves, Goblins and Orcs.
  • The Battles: The CR3 patrol scenario is replaced with two scenarios, the stand-up fight and the raid.
  • No magic, though. For that you need one of the other rules sets.

Straight off the printer, you could play pretty much any ancient or mediaeval battle, re-enact scenes from Lord of the Rings, or use your Warhammer Fantasy Battle figures for something a little different.


There are a variety of other rules sets. These use the same basic mechanics, although those released prior to 2009 use earlier editions, and as a rule THW doesn’t update rules sets for the sake of it.

You can buy them direct from THW as print or PDF versions, or from RPGNow as PDFs. They cost around $20 apiece, and most of them have supplements, many of which are available free on the web. Ones currently available include:

Ones I Have

  • All Things Zombie. Reproduce the zombie horror movie genre. These are the rules I use for the 28 Months Later campaign. They are probably the most popular of the THW rules sets.
  • Larger Than Life. Gaming the pulp fiction of the 1930s and 1940s. I used these for the latter part of The Arioniad, season 1; they’re very portable.
  • Warrior Heroes: Armies and Adventures. These are the rules I use for Talomir Nights.
  • 5150. Science Fiction. The core rules cover adventuring parties and small military units.
  • Legends of Araby. Out of print now; a precursor to WHAA, with similar rules but a setting much like the Arabian Nights.

Ones I Don’t Have. Yet.

  • Colonial Adventures. 19th century colonial.
  • FNG. The Vietnam war.
  • Nuts. World War II combat.
  • Red Sand, Blue Sky. Roman gladiators.
  • Six Gun Sound. WIld West gunfights.

There are also a number of sporting titles, but sport doesn’t really float my boat as a gaming topic, so I’m unlikely to get them.

  1. Eduard says:

    “The big thing is you get to react to what I do just like in real life.”
    Oh no you don’t… your buddy archer gets charged or your enemy slips just two meters by, and you do nothing. A house rule of “intereception reaction” can come in handy.

    • andyslack says:

      I have seen that happen when one side doesn’t activate and moves without triggering an In Sight test, but not that often (as opposed to, say, Warhammer 40K where it happens pretty much every turn). Is that what you mean?

  2. […] already reviewed Chain Reaction here, and this is really a minor update, so I’ll limit myself to the changes for this […]

  3. […] system is much the same as Swordplay, which is in turn a variant of Chain Reaction (both reviewed here), so I’ll gloss over that; being familiar with those, what I bought this for was the dungeon […]

  4. […] rules are derived from Chain Reaction, with the notable exception that nobody dies in the pulps, so the worst outcome you can get is to […]

  5. […] essentially takes the combat engine and wilderness terrain generator from Chain Reaction (reviewed here and here) and the expanded character creation, alien races, city map system, police and crimes, and […]

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