This article explores the theories I adopted when designing and developing RENEGADE. I hope you enjoy it….
Solitaire board games are a growing industry, but one not without its critics. What can we do as designers to understand why people want to play games alone, and what can we learn about the soloist that will help us make better solitaire games? Richard Wilkins is a board game designer, and presenter on the Box of Delights media site, with design credits on Mentis  and Renegade . Renegade was designed primarily as a game for soloists, and exploration in its design prompted this article.
I have a secret. An obsession. It’s mine and I’m not sharing it. Okay, sometimes I share it. Sometimes I let other people into my world. Though, to be fair, it is really me wandering over into their world, because my world is not open to invitation.
The obsession doesn’t have a great image. It’s not fashionable, it’s not hip, but it is one that is shared by a large and growing community. We call ourselves ‘Solo Gamers’, and we find all sorts of excuses as to why we play games alone. You might assume it’s because we have no one else to play with, but for most soloists this is the least of reasons . This is no substitute, because I am a selfish gamer.
Solitaire games are an escape, a way to unwind, a way to drift off into a world of our own, and forget the stresses of a modern society. Video games, TV and movies are ‘cooler’, but are way too demanding. They shout for our attention, demanding we, “sit down, shut up, and pay attention!”
But is it this straightforward? Is a solo game just like reading a book, completing a crossword, or solving a puzzle? Is it just as rewarding as filling in the numbers on a Sudoku grid? Or is there something more complex going on?
The capacity to link emotions to thinking was first described as ‘emotional intelligence’ in 1996 by American writer and psychologist Daniel Goleman . His theory says that our capacity to think and reason is influenced by the constant stream of emotional information flowing to the same part of the brain (the amygdala) that handles both memory and decision making as well as emotional responses. This theory is hardly a controversial one; we all know [anecdotally] that when we are highly anxious or frightened our ability to reason and comprehend is impaired.
So is this a two-way street? Does playing a game, or solving a puzzle, using the same part of the brain that processes emotional responses, actually not only improve our ability to think, but to also manage things like impatience, sadness, frustration and disappointment? Even something less interactive, like solving a crossword puzzle, will be firing neural links in over 30 different parts of our cerebral cortex, over and over again, thickening the myelin insulation around the axons of our brain cells . Imagine the complex development your brain is going through when you play a solitaire game like Magic Realm  or D-Day at Omaha Beach .
D-Day at Omaha Beach, Decision Games (picture courtesy of Nathan Leavitt).
“If you think of the brain as a machine, you would not expect it to function for 120 years without good maintenance. For good maintenance, the brain needs purpose – designed stimulation – such as films, music, books and well designed brain training activities. ‘Neurobic’ activities help to keep your head fit in the same way that aerobic exercises help to keep you muscles fit.” 
So not only is playing games good for our brains, it is good for our wellbeing. What if a puzzle could also deliver us an emotional experience? Then, as we learnt from Goleman, we would be upping the ante on brain training and wellbeing.
Board games, like reading a book, provide this third dimension to puzzle solving via a ‘theme’. Even some abstracts, despite their definition including the words ‘no theme’ [10a], are wrapped in a theme. In Chess, for example, we are medieval kings fighting over a chequerboard battlefield. Abstract games are superlative at pitting human brain against human brain, as each seeks to out-strategise the other in order to demonstrate their intellectual superiority in what Thompson describes as, “an exercise in logical thought.” [10b] Even the soloist can mull over a competitive abstract board, formulating opening lines and killer end-game strategies.
But how can a solo game deliver the same kind of challenge? And if it doesn’t, how then can it compensate?
It’s all about the theme
When we don’t have the company of a human opponent or team mate, then the social intelligence, the memories evoked and the emotional responses, must instead come from the game. The theme of a game is a powerful tool for evoking these emotional responses. If theme delivers emotion, and emotion contributes towards our capacity to solve and enjoy a game, then theme plays a big part in designing a good solitaire experience.
As we turn to look at how solo games are best designed, to exercise our amygdala and keep us entertained, let me leave you with some questions: can a designer tap into this link between emotion and decision making, to create a more engaging experience? Does the theme used, and the positive and negative emotions it evokes, improve or impair our ability to think? Is this a dimension that designers have yet learned to exploit? Can a board game create the same level of drama as a movie? Can a board game cause us to feel joy, surprise, horror, or fear?
Thematic games like Arkham Horror (Fantasy Flight Games) rely heavily on a narrative to deliver their immersion. 
There are limitless themes you can build your game around (sports, fantasy, culture, history) as long as it has a good story and a good set of challenges. In fact, you might say that developing a solitaire board game is more akin to puzzle creation or writing fiction, than it is to developing a competitive board game. The designer must engage the soloist with a series of puzzles, or ‘goals’, leading towards the final end state (the final goal) with an evolving story arc to take us there. Thus many of the tools of puzzle design and storytelling become part of the solo board game designer’s arsenal. Indeed, the same might be said of video games. A video game often seeks to solve the same design problems.
Investment in the Game
As a game designer keeping the soloist in mind, there are basically three options available to you: you either create a game specifically for the soloist, you develop a multi-player game with a solitaire variant, or you create a cooperative game, where all players work together against the game. Cooperatives offer their own kind of challenges (e.g. making cooperation necessary; not allowing one ‘alpha’ player to dictate every play), but very often can be played solo, with a single person taking the role of more than one ‘player’. There are limitations to be aware of though. A cooperative game doesn’t work well solo if it relies on hidden information, or if it introduces a ‘traitor’ element where one of the players is secretly working against the rest of the group. But a cooperative game shares many of the challenges that a pure solo game faces, since in both cases the players are not necessarily competing against each other, but against the game.
The gaming community today makes many demands on a new game to provide a solo variant. It is often one of the first questions asked on BoardGameGeek forums. This offers an economy to the soloist, because it means they can take the game to a club or family game night to play with others, as well as being able to play it solitaire. But there are a couple of things the designer should keep in mind. A solo variant should challenge the soloist to use the game mechanisms in the same way as they would multi-player. As much as possible it should be the same game, governed by the same rules, played in the same way. This allows the soloist to hone their strategies, bringing practiced skills to the table when they play amongst friends, as well as giving them the same kind of ‘user experience’. Otherwise, “you’ll end up in a situation where you’re designing two games with the same components” .
The solo variant should also be able to adjust its difficulty or, if relying on randomness, present a win:loss ratio that reflects the investment in effort the player has made. The longer the game, the higher the ratio of wins to losses should be (e.g. 80% win-rate for a 1-2 hour game). With a short game, the win:loss ratio should be reversed (e.g. 20% for a 20min game). This means that with a short game, a soloist can play 4 or 5 times in one session to seek the win they are looking for. Of course, there are exceptions to this. Some designs are notoriously difficult and take some considerable time to play , but the compensation (i.e. its ‘reward’) is an immersive experience that leaves the player satisfied with the outcome, even in defeat. After all, many a good story has a tragic ending.
More than anything though, many soloists demand that the game is ‘fair’ – that any loss is due to the player playing badly. The importance of this requirement increases as the player invests more in the game. There is, therefore, a fine balance to be struck between ‘predictability’ and ‘randomness’. A good solo design is one that is neither too random nor too predictable.
The AI Opponent
There are many tricks a designer can use when developing a solo game or solo variant. A solo game should appear to respond to the player’s actions and/or the game state. Unlike Sudoku and crosswords, the solo game fights back, and the soloist wants a challenging opponent! Should a solo game’s virtual opponent be able to pass the Turing Test ? I don’t think so, though it’s not as difficult as it might sound. The game is operating in a very limited domain, where only the rules of the game matter. It doesn’t need to comment on last night’s football result, or mock you when you make a bad move. Instead it needs to present the player with a challenge that can be met using the mechanisms the game provides, and to do so at a level comparable to a human opponent. Computer Science, with its increasingly boundless capacity for calculation, is still seeking that prize.
But the concepts in developing a board game ‘Artificial Intelligence’ do share some similarity to those used in computer science (except that the board game AI has much less capacity, even than a 48k ZX Spectrum!) The designer must remember that the board game AI will be acted out by a human player using rulebooks, playing cards, cardboard chits and dice. You can’t ask a human player to execute a 3-ply lookahead, evaluate each position, and thereby pick the optimal move for the AI. Either the AI is heuristic or random, but most often is a combination of both. Even so, you can develop an exceedingly complex heuristic within a computer program that cannot be executed by a solitaire gamer without making it hard work.
I have toyed with the idea of ‘programming’ a game AI using punched-cards, as this is a physical medium that could be packaged in a box and still be seen to be within the realm of traditional boardgaming. Today, though, technology can help us solve this problem. You can now find many games now that supplement the physical cardboard, plastic and wooden pieces with digital apps on iPhones, iPads and Android, introducing radical new concepts to the board game experience, like real-time events or augmented reality. 
Augmented reality board game “Roar! Catch the Monster”, by Trefl. 
Chess computers have been doing the full AI thing for some time, and we can even play against them on a physical board. But even if they can’t pass the Turing Test (are these machines ‘thinking’ in the same way a human player is?), given that their routines are so complex, is it feasible to ask a human player to act them out on paper?
“Saying that Deep Blue doesn’t really think is like saying an airplane doesn’t really fly because it doesn’t flap its wings.” 
Chess computers use a combination of scripted openings with the extreme number crunching capabilities of a CPU to look ahead and evaluate possible predicted game states. Their strength lies in both the sheer volume of computations they can make, together with the comprehensiveness of their evaluation routines. But the thing with chess is, the Queen won’t suddenly conjure up a goblin and then turn you into a frog! This is where thematic games can use randomness, an essential ingredient for solo games, to introduce plot twists into a game that is more akin to an emotional experience like reading a book or watching a movie. So what are the tools available to us when developing a playable AI that offers both fairness and unpredictability?
The Designer’s Toolbox
The toolbox for the solitaire games designer is diverse. We can use procedural flowcharts, decision trees and heuristics; random dice rolling, card draws and draw cups; as well as some more advanced techniques like the ‘copycat mechanic’, ‘game memory’ and ‘response-effects’, all of which are discussed below.
Many solitaire games are procedural. They use flowcharts, decision trees, formulas and algorithms. Wargamers are very familiar with lookup charts that direct enemy forces according to a set of rules reflecting the current game state. The joy in highly procedural games is watching the game play out whilst you follow the ‘script’. These scripts will dictate the changing state of the board and can encapsulate the ‘AI’. But just like ‘predictability versus randomness’, the scripting mechanism operates on a sliding scale. At one end the script is very fixed and is followed like one might read a story; at the other end, the script becomes a complex heuristic that is sensitive only to the game state. Too far down the scripted route and it ceases to be a game and is instead more like a theatrical play; too complex a heuristic and players are spending more time working with the algorithms and mathematics that it becomes more like work than play (unless of course you like that kind of thing!)
Wargames in particular can be very rich in detail as they try to simulate historical battles and the individual behaviours of different types of units. One game that flirts dangerously close to the limits of procedural play for the thematic soloist is Navajo Wars (GMT Games) , in which players are constantly following a flow of steps that dictate “if this, do that”, schematised via flowcharts.
But it pulls it off by mixing in a programmed ‘Order Matrix’ to drive the enemy responses. This order matrix might get adjusted by a card pull or be set up differently according to story-driven scenarios. These individual orders dictate which flow-chart to work from, so you can never be totally sure how the AI is going to react. It preserves playability by making each individual flow-chart short and quickly executed with practice.
The ‘order matrix’ from Navajo Wars, GMT Games.
But the procedures don’t have to be complex to be effective, and they can be very playable. For example, Gears of War  was one of the first games I saw that introduced a card pull that listed a set of ‘IF, THEN, ELSE’ routines to drive the behaviour of the alien protagonists. Similarly, for wargamers, Frontline: D-Day  offers a solo variant via its “tactic cards” to control enemy troops with conditional orders. These simple rules allow the game to appear to respond to the game-state, no matter which random card is drawn.
So, once more there is a balance to be struck, and this is where randomness plays its part. Card draws, dice rolling, and drawing from bags or cups, all provide randomness. Cards drawn from a shuffled deck often have context sensitive text, whilst dice rolls and cube, token or chit pulls allow you to associate more complex instructions to them in the game rules. In Snowdonia  for example, the soloist draws 6 cubes from a bag, which is itself limited in supply until repopulated via player actions, and these cubes represent the different resources available to the player next turn, as well as potentially triggering the next step in the scripted sequence of ‘events’ the game throws at the player.
Snowdonia, from Surprised Stare Games.
One other effective technique is what I call the ‘copycat’ mechanism, where the game’s AI opponent copies an action taken by the human player. Race for the Galaxy: The Gathering Storm  uses this mechanism to good effect, in combination with procedural routines selected by dice-rolls. The ‘robot’ opponent has a set of scripted responses, to an action determined by the roll of action dice. Should one of those dice show the asterisk symbol, then the robot copies an action of the human player. It works because it is procedural, unpredictable and is sensitive to what the human player is doing.
Race for the Galaxy, Rio Grande Games.
The robot AI in Race for the Galaxy is even more impressive because it appears to have a ‘memory’. The action board that records the player and robot actions has two tracks on it, which are advanced or moved backwards in response to both the actions of the player and the actions of the robot, such that the “IF…THEN” routines of the AI, which are influenced by the state of those tracks, respond differently as a result of the previous turns in the game.
One of my favourite mechanisms is the ‘response-effect’ mechanism. In many ways this is similar to the ‘memory’ mechanism, in that something that has happened in the past dictates what happens in the future. One of the first games that introduced this idea most effectively was Robinson Crusoe: Adventure on the Cursed Island . Random card events present the soloist with a decision. If they choose to accept the short-term benefit of the card, then the card will be shuffled into an Event deck that is drawn from each turn. Here’s the catch: this card will have a negative effect that the players now know is coming, but they don’t know when. For example, they may choose to eat some mushrooms to satisfy their immediate hunger, but in a few days time (each game turn is a day) this card will get drawn and give them a stomach ache, unless they can find a cure in the meantime.
Robinson Crusoe: Adventure on the Cursed Island, Portal Games
Did I win yet?
Finally, you will need to pay some attention to your game-end state. In competitive player-versus-player games it’s easy: one player beats the other(s) and it’s game over. In solitaire games you need to create one or more game-ending conditions that can be satisfied by the game state alone (oftentimes this is exercised by a ‘timer’ ). Like any good story, it should not be anti-climactic. The game needs to build to a crescendo of tension that has the soloist gripped by the drama until the last death. For many this climaxes in a ‘you win / you lose’ decision; for others a game best ends with a victory point count, by which they can measure their success and compare it to previous victories (or defeats!)
Whichever you choose, there is no right or wrong; every gamer will have their preference, and every game will have a better fit. Solo variants for games that play more like multiplayer solitaire games, normally with players competing for shared resources, adapt well to a victory point type ending. Story-driven games on the other hand, fit better with a conclusive and binary ending, that either has the player winning with “happy ever after” or losing to a fateful tragedy. This is where the designer delivers the drama that engages the players and gives the emotion we are looking for.
Soloists may enjoy gaming as both a solitary and a social activity. But solo gaming can be a passion in its own right. It does not exist merely as a substitution for playing with others. If you are looking to design a game, or seeking to understand your potential market, remember the soloists. We are not just in pursuit of happiness and relaxation: we want to exercise our minds, to be challenged and be told a good story. Puzzle designers, crossword writers, video game designers and storytellers, we need you. Every visual, numerical, recollective, empathetic and linguistic challenge you deliver to our brain will teach us to be more creative, critical and reflective thinkers, more emotionally intelligent and it may even make us happy. Above all, remember the balance you must strike when building a solo design. Make it playable, replayable and rewarding; make it immersive, unpredictable and make it fair. Then we’ll play your game, even if we won’t let you play it with us.
Thanks to Néstor Romeral Andrés for his valuable feedback, and to Nathan Leavitt for allowing the use of his photograph of D-Day at Omaha Beach.
References & Further Reading
 ‘Mentis’, designed by Richard Wilkins, published by Nestorgames, 2013. Mentis is a 2-player abstract that uses pieces of three different types, each immune to the attacks of one other type, and each with a movement of 1, 2 or 3, and a converse attack range of 3,2 and 1 respectively. Meant as a faster alternative to Chess, with pieces deployed from the hand, the ability to deploy and move the pieces in stacks, and with capturing done without moving (rather than the move and capture mechanism of Chess). http://www.nestorgames.com/mentis_detail.html
 ‘Renegade’, designed by Richard Wilkins, published by Victory Point Games, 2015. Renegade is a solo/cooperative game for 1-4 players. Thematically modelling ‘hackers’ on a computer network, at its heart Renegade is an abstract, played on a modular board, with an evolving deck of cards used to generate the commands necessary to enact change on the board. http://www.victorypointgames.com/renegade.html
 The ‘1-Player Guild’ has 3,350 members (Nov 10th 2015) with an active forum for discussing solitaire board gaming. https://boardgamegeek.com/guild/1303
 Davies,Phil, ‘So, why do we play solitaire games?’, Board Game Geek, Feb 2014, https://boardgamegeek.com/thread/1116545
 Goleman, Daniel, ‘Emotional Intelligence: Why it can matter more than IQ’, Bloomsbury Publishing PLC,1996
 Horne & Wootton, ‘Teach Yourself: Training Your Brain’, 2007
 ‘Magic Realm’, designed by Richard Hamblen, published by Avalon Hill, 1979, is a complex fantasy role-playing board game, for 1-16 players, with detailed rules covering all sorts of events that might be encountered in fantasy literature; fighting, tiring, resting, exploration, hiking, trading, hiring retainers, magical effects, it’s all there.
 ‘D-Day at Omaha Beach’, designed by John H. Butterfield, published by Decision Games, 2009, is a hex and counter wargame, with over 350 counters, and with each unit representing the equivalent size of a US Infantry Company in the assault on Omaha Beach during WWII. The map itself represents an area of beach 9km long and reaching 4km inland. Each turn in the game represents 15-30 minutes of the actual day, from 6am to 6pm. Players will be having to manage unit stats on each of the counters, terrain effects from the map, as well as a set of charts and reference tables.
 Gibb, Dr Barry, commenting on the Nintendo DS range of electronic brain trainers, Rough guide to the Brain, Times2, 29/09/2007.
[10a] [10b] Thompson, J. Mark, ‘Defining the Abstract’, The Games Journal, July 2000, http://www.thegamesjournal.com/articles/DefiningtheAbstract.shtml
 ‘Arkham Horror’, designed by Richard Launius and Kevin Wilson, published by Fantasy Flight Games, 2005, is a highly thematic cooperative adventure game based around H.P. Lovecraft’s ‘Cthulhu Mythos’. The game delivers a series of story driven events that have the players collecting clues from various locations and closing gates to other dimensions, each occupied by fear-inducing monsters, on a map representing the town of Arkham, before climaxing with a battle against a great ‘Ancient One’.
 Pederson, Morten Monrad, ‘The Compelling Power of Solo Play for Tabletop Game Kickstarters’, Stonemaier Games, 14 Jan 2015, http://stonemaiergames.com/the-compelling-power-of-solo-play-for-tabletop-game-kickstarters/
 For example, ‘Robinson Crusoe: Adventures on the Cursed Island’ , is notoriously difficult for players to win, but is still very popular. It ranks at #14 on boardgamegeek.com which cites a playing time of 90-180 minutes.
 Turing, Alan, ‘Computing Machinery and Intelligence,’ 1950; It opens with the words: “I propose to consider the question, ‘Can machines think?'”. Because “thinking” is difficult to define, Turing chooses to “replace the question by another, which is closely related to it and is expressed in relatively unambiguous words.” (p.433). Turing’s new question is: “Are there imaginable digital computers which would do well in the imitation game?” (p.442) In other words, could a machine exhibit behaviour indistinguishable from that of a human.
 For example, ‘The Loebner Prize in Artificial Intelligence’, initiated in 1990 by Hugh Loebner in association with The Cambridge Center for Behavioral Studies, is a contest designed to implement the Turing Test, http://www.loebner.net/Prizef/loebner-prize.html
 For example, ‘X-COM: The Board Game’, designed by Eric M. Lang and published by Fantasy Flight Games, 2015, replaces the rulebook and controls the game events and the actions of your alien opponents with a digital application that directs the flow of the game in real time.
 ‘Roar! Catch the Monster’, designed by Hubert Spala, published by Trefl, 2015, is a game that uses augmented reality via a grid board, recognisable to a digital application via the device’s camera, to track the position of an invisible ‘monster’ that players are seeking to find. Audio clues are given to the players via the digital device’s speakers, whilst the app tracks the position of player tokens, as they move them around on the physical board, again via its camera.
 McDermott, Drew, professor of computer science at Yale, ‘Yes, Computers Can Think’, The New York Times, 14th May 1997. http://www.nytimes.com/1997/05/14/opinion/yes-computers-can-think.html
 ‘Navajo Wars’, designed by Joel Toppen, published by GMT Games, 2013, makes extensive use of text in modelling the survival of the North America Navajo, from the time of the Spanish incursion in 1595 to their subjugation by the American army in 1864. Card draws describe game events, and player actions describe player responses, and a set of flow-charts and tables tell players how to act out those events and actions.
 ‘Gears of War: The Board Game’, designed by Corey Konieczka, published by Fantasy Flight Games, 2011, is a translation from video game to board game, and uses ‘AI cards’ to spawn and give actions to the enemies via a simple set of ‘if, then, else’ rules which query the game state. e.g. a card might say something like, “if there are locusts on the map then move them 1 room closer to the heroes, otherwise spawn 2 locusts at the exit.”
 ‘Frontline: D-Day’, designed by Dan Verssen, published by DVG, 2010, is a text-driven simulation of the D-Day landings, with cards and counters representing Allied and German soldiers and vehicles, as well as the landscape (instead of a game board or map). It also uses a set of Tactic cards to govern the game’s decisions. The tactic card offers a general instruction, as well as how opposing units recover, which of the player’s units they will target, what attacks they will perform and any special instructions in response to the game state. For example, a Tactic card might read, “If a Section Advances into Open Ground or Stream, Advance it a 2nd time.”
 ‘Snowdonia’, Surprised Stare Ltd, designed by Tony Boydell, published by Surprised Stare Games Ltd, 2012
 ‘Race for the Galaxy: The Gathering Storm”, designed by Thomas Lehmann, published by Rio Grande Games, 2008
 ‘Robinson Crusoe: Adventure on the Cursed Island”, designed by Ignacy Trzewiczek, first edition published by Portal Games, 2012
 For example, ‘Mage Knight Board Game’ designed by Vlaada Chvátil, published by WizKids Games, 2011, asks that the game be concluded after a fixed number of days and nights have passed, as dictated by the scenario being played. Mage Knight Board Game will have multiple turns per ‘day’ and ‘night’, during which players are exploring a modular board, representing a magical land full of rampaging orcs, dragons, villages, cities, castles and dungeons.