Games Concepts
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Game Concepts

These pages describe mechanisms and guidelines for the development  of games (board games), more specific games that can be played in social environment (friends, family, etc.). The building block links gives you some detail information on mechanics. The RPG/War gaming link gives you insight in these types of games (in case you are not familiair with them) and the Game Theory page tells you all about the more mathematical/ social/ economical point of view on games (biddings, etc.). At the moment I'm pretty much into the mechanics of Games Workshop, as these are good representative mechanics of 'adventerous real life'. Examples are Mordheim and BloodBowl. I actually translated the rulings in to Dutch (also to get a complete grip on the rulings).

I do not intent to suggest / prove / imagine / ... that I am a game-guru. In general, treat all my notes as wrong. Consider these pages as note pad of my thoughts, which might be usefull to you.

In the Games_UC you will find some of the things i'm playing with.

If you want an instant link, check TheGamesJournal

Introduction

As I love games, I even more love the mechanics of a game. Below you will find some of the common and uncommon mechanics I found (Most of them are 'open doors', but are here for inventory sake). You can use these when developing your own games.  Also, this page counts as reminder to myself. If you have comments, please let me know. The guidelines should help you avoiding ending up in this list.

I started off with describing some of the game mechanics, I still have to do a analysis on them, but here is some work so far.

I also noticed that game mechanics are essential to a game but not the 'striking' part. At least as important as the mechanics are the theme and the look&feel. Some games are pretty boring despite great mechanics, but because of missing look and feel.

What is a >Game< anyway?

In a economical (competitive) environment, the word 'game' is used to describe the actions, reactions and strategy of players in a closed environment, e.g. a bidding for a telecom environment or market competition. It also is used to describe interactions between agents who to want to optimize their utilization/profit/etc, anything that is required to achieve their goals. As such a lot of (mathematical) theory has been developed (especially over the last decades) in order to explain economic behavior. Experts in this area seem be consulted more and more when it comes to biddings and strategy development in general.  Games are also used as models for reality in order to simulate/verify strategic decisions. War games are as old as civilization, whereas real-life generals have fought wars on a table tops in order to analyze their strong and weak point in order to sharpen 'real-life' strategy (I don't want to state that real-life war is game, but according to the definition, it actually is with the remark that games are just models / representations of reality). Games are also used more and more in assessment trainings as part of applications in order to gain insight in the behavior of people in simulated (but controlled) situations. As such games can also be seen as an escape from real life (e.g. roleplaying). 

In social/family environments, games attempt to represent reality (as described above), as such a game is subset of reality in an abstract (model) form. A game is a (safe) way to experience facets of reality and to learn from it. The educational aspect of a game is not to be underestimated, some games are actually designed to sharpen your brain. Many children learn to cope with real situation based on experiences from games. These experiences range from social interaction, learning to deal with new situations, analyzing 'what-if'-situations and/or to gain logical overview. In addition it adds joy and fun and other social aspects with regards to the relationship with the other players.

"A game is defined by its system of rules," wrote Claude LÚvi-Strauss in Structural Anthropology.

"Game := (abstract) simulation of a subset of reality within certain given constraints (wrote I myself)

In these pages I will concentrate on the 'normal' games and the development of these games, keeping gaming theory in mind though.

The main characteristics of a game are:

bulletclosed environment with formal and unambiguous rules and goals
bulletin general a model of a sub-set of reality
bulletin general interaction between players
bulletas a rule: a safe end, no one gets hurt (neither physical / mentally / financial) (betting games are an extension of games, as all betting game can be played with tokens in the first place).
bulleta game sets goals for player to achieve

A basic principle of a game is that is a 'closed environment', everything that can happen must be captured by the rules and the game has clearly its boundaries. The rules are clear and unambiguous. The worst thing that can happen to game is that players get a into deadlock, because the situation is not covered by the rule. A typical example: in Risk various house-rules may apply. In general, before the game starts, players decide what rules apply. In general a game in some way or another confronts the player with 'reality'-alike situations, whereas these situations may be abstract. Games are about winning (conflicts), puzzles (knowledge, intelligence), strategy (decision making) and appeal to our basic needs of competition, exploration, self esteem, learning and socializing. It even may give the player the opportunity to step out of his current life and become that pirate, hero or whatever fantasy the player may have. These basic needs also require interaction in a game, as this happens in reality as well.  The good news with games is that after a game (in general), people can face each other again as real-life persons. [I have noted though that some games show unknown (sometimes unwanted) sides of people, but let's not go into psychology. Note that as already stated, games (simulations) are being used on many occasions of applications to test the personality/skills/etc. of the applicant]

One other thing, the game should be dynamic, interaction between system / players should be available, otherwise it would be more like a puzzle (please note, that some are actually one-time-playable games such 211B baker street or how to host a murder party, which are actually puzzle games...).

If we are talking about family games, one should also keep in mind that the look and feel of the game should appeal to the players. Looking from a technical kind of view, you can set the environment of the game in any direction, that might appeal. A Star Wars Monopoly variant, targeted at Star wars fans, has not really a link to Star Wars, other than the game-environment (Star wars figures / places instead of the ordinary pieces). This all is linked to individual taste of the to-be players / buyers of the game. Some notes on this subject will be given later. 

These days you see lot of games that are changing all the time due to new add on's (see below: defined vs. changing games) and these game gain in popularity. This changing / add on feature is practically a part of the game. They actually make possible to customize the game to the players whishes, so in practice, two groups of players can play the same game (by name) but they would be playing in nearly complete different game environment (e.g. Settlers and Space Settlers / Magic in the different types / Roborally and its different add on's), what remains are the basic mechanics. Especially Games Workshop is good in this concept, keeping the basic mechanics but with different twists (Warhammer, Warhammer 40k, Mordheim, Warhammer Quest, etc.).

What is a >good< game then?

First give me your definition of 'good' and I'll tell you. Pokemon is a game that probably broke some sale records. Is it good game? Not really, but it sure boosted the profits of WotC. The concept is interesting, but heavily stolen from Magic The Gathering. It sold heavily thanks to the marketing guys, the Pokemon Virus in general and the everlasting will of people (kids) to collect. Consider it a temporary hype. The game will die in a few years (estitmated death in 2005), but the game mechanics and concept will remain.

In general it depends on the players mind set: does he prefer luck, tactics and/or communication?

A good game, in my opinion, is a game with 

bulleta straight goal
bulletgood mechanics 
bulleteasy instructions
bulleta good, intuitive look and feel
bulleta (intellectual) challlenge to the players
bulletgood interaction
bulleta limited time of play
bulleta challenging environment
bullettime for beer and pretzels
bulletand optional: something to collect in-game (tokens, cards, whatever)

In addition I personally prefer games where all players stay in the game until the game is over (I hate waiting). Another interesting question: does the best player actually win (most of the time) or does the game support handicaps (e.g. Go)?

These mixed in the right combination and heavily marketed in a way that makes it everlasting will bring you the block buster you were looking for. In practice: a game that will be played for decades (centuries in case of Go, Chess; decades in case of Aquire, Warhammer, Cluedo, Monopoly).

Wolfgang Kramer identifies the following critical succes factors:

bulletOriginality of game (not sure whether he means theme, mechanic or more something in general)
bulletFreshness and replayability: the game should be different each time with the same amount of fun
bulletSurprise: each game played should carry unexpected surprises
bulletWinning Chances: each player should have the same chance of winning at the start of the game, for some game in particular: if the players are skilled in the same way
bulletNo 'Kingmaker effect': even though one player could an advantage early on, other players should still have a chance to win
bulletNo early elimination: all players should stay involved until the end of the game
bulletReasonable waiting times: or have other players take action during the other players turn (e.g. chess)
bulletCreative control: the player should be in control rather then 'being played'
bulletUniformity: the title, theme, format and graphics should give a unified impression (e.g. the art should be coherant: note: Magic is a positive exception)
bulletQuaility of components: durability, functionality and visual appeal 
bulletTarget groups appeal: game should be consistent in the use of luck, strategy and communication.
bulletConsistency of rules: speak for itself I guess
bulletTension: although a game does not need to have the same tension during playing, it should at least have a few peaks
bulletLearning and mastering the game: start quickly, learn easy. A game should offer the possible to build up skills. An example sheet usually helps a lot. 
bulletComplexity and influence: short, simple games must have short, simple rules.  Complex games, on the other hand, may have more complex rules. Complex games are not problem if they offer enough challenges.

Speaking for myself, Aquire is game that gave me lot of fun, I learned the game in less then 10 minutes, but still enjoy a 'good game of Aquire'. I think Risk is a very challenging game, but knowing it takes for hours (days?) to end a game really disencourages me to play the game anymore. For Aquire, once all the tiles are layed, the game is over (in less than an hour). Should I mention that I think that Monopoly is a boring game? Neeh.

Marketing of a game

Should I tell you the story of the best VCR type ever (V2000 produced by Philips) and the worst one (VHS by Sony)? Neeh, you propably know the story, it's called marketing. Ever wondered how a relatively poor mechanism has sort millions of times (Pokemon games? Starwars games?). It's a question of marketing, franchising, etc., and has nothing to do with a good game.

Skill games vs Luck games

Some people argue that dice games are luck games anyway. I guess that is not true, since you can 'foresee' what might happen and base a strategy on that. On a single dice you know you have 6 outcomes with equal changes. However, the more dice you introduce the more chance you have the outcome will be close to the average. Here again you can set a strategy. Look for instance at Risk, where can predict the outcome more or less and base you strategy to it. And if you loose against the odds, well, that's life.

Actually (some kind of) luck is a basic ingredient to most of the games since it reflects the unexpected in life. Using dices may spoil any good game, but in the long run dices or other random (but predictable) generators (like cards) can actually contribute to the joy of playing. 

Themes vs mechanics

This is an interesting one. If you start to break down games, based on mechanices, you suddenly notice that games with a complete different theme has exactly the same mechanics as the game you are just analysing. And then again, you like one game above the other. How come? Simple, the theme has more appealing to you. 

If you look at a game called 'Witch' (free demo download here), it looks like a real fun game. Actually it is, but if you break down the game, you will discover that the mechanics are quite familiar with some kind of non-collectable Pokemon/Magic game. If you would add some extra rules to a standard card set, there is no need to buy this game (read: the rules). Nevertheless, the Look&Feel and the complete atmosphere of the game cannot be copied...

Themes and atmosphere are major compenents of the game. Some classical games, such as Go, Chess or Poker don't have a theme at all. If you look for instance at a game like Set!, the cards could have any symbols or pictures (e.g. houses, boats and cars). The simplicity of symbols (rectangle, oval and tilde (~)) is to me a major contribution to the fun of game, since it keeps game to its basics: just using abstract symbols.  One could have build a complete (fictional / historical) story around the game with related pictures. No, the game is just presented in its bare form. For game it actually works, a game of Warhammer without models and story line would be absolutely boring. As already mentioned in the card game section of my inventory list, most of the game (Star Trek, etc.) solely depend on the theme, the game itself would be boring to death. 

An interesting analysis is done by Andrew Hardin, by breaking down the game Magic the Gathering. His conclusion is the theme is paramount, without the wizards, dragons and all other fantasy ingredients, the game looks quite silly. 

A great game nowadays with a theme perfectly combines theme and mechanism. Like in: if you are playing a war game, you actually want to 'feel' the war. 

Conclusion: unless you cannot come up with a great new concept, make the look the look and feel paramount, as it distracts your customers attention away from the poor concept :)

Analyses of the various types of games

[note: the information below will be put in a seperate page at short notice]

Chris Crawford perceives five different types of regions: board, card, athletic, children's and computer games. This is probably a somewhat out-dated classification, as he describes card games as games to be played with 52 cards and also overlooks new game mechanics (note that he wrote his original paper in 1982, so he is not to blame). He overlook Magic and other CCG's, in addition he overlooked extensible games I guess.

Funagain games made a distinction between some of characteristics of games, based on format, genre and theme. Without a complete sum up, here are some examples:

bulletBoard game format
bulletCard Games format
bulletPlacement/ Tile-Laying Games format
bulletBooks format
bulletTrading Games Genre
bulletRole-playing Genre
bulletRail & Network Games Genre
bulletSpeculation Genre
bulletCivilization Building Genre
bulletAbstract Strategy Genre
bulletWar and Combat Genre
bulletRacing Games Genre
bulletMaze Games Genre
bulletHistory theme
bulletBusiness Theme
bulletReal Estate Theme
bulletFantasy Theme
bullet....etc.

Games can be divided in many ways, but I think that dividing them based on their physical appearance only is not correct. I guess it's better to first look at the main mechanics (note that mechanics can be combined). This doesn't mean the distinction between type, genre and theme is not valid, especially the theme is important, since that will attract players in the first place (Another Star Wars-alike theme will attract Star Wars fans anyway).

Another way of looking at games is the time you (have to) spent on it, either by learning (not just the rules but also the different strategies) or by preparing / having fun with it by yourself (e.g. collecting, painting, preparing a strategy, etc.). This would lead to

bulletFamily type games: easy to learn, not much preparation, can be played with fun without much preparation / learning, fast play (usually be played within one hour or less). Typical example: many card games, Settlers, etc.
bulletDevotion games: games that require training / learning before fully understanding the game and usually require some hours of playing. Usually you will find pro's in these kind of games. Typical games are Chess, Go, etc.
bulletHobby games: games that are hobby on their own, you can spend all your spare time to any game that belong in this category. Usually expensive, lots of learning and training, specialized players required. Some games have pro's. Typical examples are Warhammer, Magic, etc.

Another typology was found in the newsgroups (rec.game.board):

bulletCategory A = If success in the game is significantly dependent on strategy with luck and diplomacy having only a minor impact on the outcome.
bulletCategory B = If success in the game is more dependent on strategy or diplomacy than on luck.
bulletCategory C = If success in the game depends on approximately equal parts of luck and strategy or depends on approximately equal parts of diplomacy and strategy.
bulletCategory D = If success in the game depends more on luck or diplomacy than on strategy.

Note that there is no such thing a a 'better taxonomy', there are just different ways of looking at games.

Customizable Games

A customizable game is basically just a set of rules. Players can choose between several elements of the game they want to use. Thinking in traditional games, consider Chess where players can choose the number of pawns they want to use, the kind of board they want to use (10x10 instead of 8x8), can set up the pieces as they want (according to additional rules, etc.), thus creating new situations and variations all the time. Typical examples of customizable games are CCG's and alike,  but also games like Roborally, where you can use the different boards to set up new tracks. In general, customizable games usually come with add on's, helping you changing the game all the time. Also games like Warhammer and alike are typical (and highly) customizable. 

One of the most interesting customizable games is Games Workshop. I'm not familiar with the history of GW, but I guess it is build around individual characters/units forming an army. The rules are given for the individual units. Based on these rules you can come up with various variations. If you look at GW, the following games from GW are available: Warhammer, Warhammer 40K, Bloodbowl, Mordheim, Warhammer Quest, etc. They all share the basic mechanic: the (unique) individual characteristics and rules of the models and their interaction with other models. There is one other important point to the GW: the models. You can customize them (glue, paint, etc.) in any way you want, thus representing your personality in the game. This is just a hobby on its own, just like the creation of scenery (some people actually only collect the miniatures, never play the game). 

Collectable games

A relative new phenomenon are collectable games. You buy some kind of starter set and with this starter set you can play other people. It is of importance that each players hold his own play materials (these can be cards, models (such a miniatures of Games Workshop), whatever). You are able to buy additional stuff to the game in order to improve your starting position or to change your strategy. As a matter of fact, you can collect these items. There are various variations to this idea:

- collectable card games / customizable card games / trading card games (CCG or TCG), e.g. Pokemon, Magic the Gathering

- collectable models/representations, each with different characteristics e.g. Warhammer, Legends (stratego variation)

- collectable dice games such as Dragon Dice, Star Trek and various sports games.

- other e.g. DiskWars (more or less a combination between CCG's and Warhammer).

Note: in any good collectable game it is never possible to buy 'THE' winning combination, as all items have their advantages and disadvantages (see "non-transitivity" below). 

Some games offer you to buy the things you really want (mostly customizable games though, but also games in the Games Workshop series), other games (especially CCG's) only offer randomly packed items. In addition, the items are packed commonly, uncommonly and rare. Should I mention that the rare items are more powerful (esp. in combination with other cards)? Neeh. In case of popular games (like Pokemon and Magic), highly sought rare cards can become pretty expensive, the top item of Magic the Gathering is priced at a few hundred Euros.

Note that for some games you really don't need to buy additional stuff as can you play a good game with just a few starters (50 Euro), for others (e.g. the Starwars CCG) be prepared to pay about 100 Euro or more in order to have enough cards to really switch strategies. The Games Workshop starter boxes usually come at 75 Euro, collecting one good army (with reserves) usually costs about 300 Euro (and then you have ONE army of ONE race, where you really want several armies of several races...). In short, these kind of games are highly addictive once you start to like them, but most of all, they become VERY expensive.

Collectable games are usually customizable games. It also should be noted that a lot (most) of the CCG's are hypes. So far only Magic survived longer than 5 years (as far as I am informed).

Symmetric vs. A-symmetric games

In symmetric games, all players start equal, and all players have the same goal. Based on luck and/or strategy, the players will diverse in game-power over time which lead to a win/loose/tie situation. In a a-symmetric games, players start (either randomly or chosen by the players themselves (or of course a combination of random/chosen)) with

bulletdifferent characteristics (e.g. D&D games)
bulletdifferent starting positions (e.g. Risk)
bulletdifferent rules (e.g. Axis&Allies)
bulletdifferent goals (e.g. Risk)
bulletcombinations of above

Especially in a-symmetric games it is of paramount importance that none of the starting situations is a-priori winning situation. Typical examples of symmetric games are Dames, Go and Monopoly: all players have the exact same starting position. Chess is also a-symmetric as Queen and King positions are different for both players, but it's nevertheless balanced. 

Note the symmetry may give some food for discussion. I stated that monopoly is symmetric, from the start yes, but luck makes the game a-symmetric over time as players hold different streets. I argue that most normal cards games (poker, etc.) are a-symmetric as players hold different cards but can choose from different strategies, but then again one could argue it is symmetric as from the start no one holds any cards and only luck can help them. Hmm...

Non-Transitivity

Each initial situation of a game, especially in a-symmetric games, should have it advantages and dis-advantages and actually a strategy/luck factor should give the advantage: non of the starting situations should be dominant (and a priori winning). In case that one starting position / strategy is dominant, the game is broken (this happens in several CCG's where new cards in combination with older cards become an easy to win combo, in such cases cards get banned and/or get rules updated)). 

In order avoid these situations, the different starting positions should be non-transitive. Consider a situation where A is better then B, and B is better than C, common logic would lead to the conclusion that A would be better than C. Such logic situations are called 'transitivity'. Non-transitivy means that this cycle is broken. Best example of non-transitivity is Rock-Siscors-Paper, non of the choices is dominant. Here goes A is better than B, B is better than C and C is better than A. In game theory this phenomenon is known as non-transitivity.

In games, this is a mandatory requirement, because a starting position (especially in a-symmetric games) could be dominant to the game, giving the A better than B better than C, starting of with A is winning a-priori. 

I think the best (and simplest) example of non-transitivity in family games is Stratego, where all units can kill the 'lower' units. The spy is the lowest in order, but the only one that can kill the field-marshal (highest in order).

If you look a card games, non-transitivity can be achieved by dealing more cards, and thus giving the player the ability to play a strategy (for instance, by fully using the advantage of stronger cards and using the weak cards to pull out the opponents strong cards). If players would be dealt just one card, the outcome would be clear rightaway. With more cards, you can try to force other players to play their 'aces', while trying to keep yours.

complete / incomplete transitivity

One can distinguish complete non-transitivity, nearly complete non-transitivity and incomplete non-transitivity. In a complete non-transitivity game, players start more or less equal. 

Before explaining what I mean, let me give you some examples complete non-transitivity: Chess and Stratego are complete, each player holds exact the same individual non-transitive tokens / game parts. One other interesting part: each players knows exactly what the other player holds. 

In nearly complete non-rancidity games, players can start with off different parts (eg cards / models etc.), but the individual parts are rated while the sum of the parts should be same for all players. If you would rate the individual parts and sum these individual ratings, each players would start with the same total 'power'-value. 

In  non-complete non-transitivity games, the individual part are not rated, so it may lead on a dominant start for one of the players, due to combinations (see the examples below).  

Examples of near-complete non-transitive games are Warhammer, MLB Showdown and Diskwars. All parts are rated and the sum of the individual parts is (or at least should be) the same for all players. Note that these ratings are arbitrary (set by an 'independent' organization such as the publisher). 
More in depth: in MLB Showdown you put their team together, where the different players have different value for attributes as well as power cards and weak cards, but where each card has a power value itself. Teams (as collection of cards) may not exceed a certain maximum value. Since every player has the same maximum, the starting positions can be considered equal.
The same mechanism can be found in Warhammer (X.000 point armies with X varying from tournament to tournament).

Examples incomplete non-transitive games are Magic and Pokemon, this goes especially for combinations, available at the start of the game . The player is able to set his starting point (more or less). Enhancements of the rules (such as banning cards, limiting other cards, changing card-rulings) have to overcome starting domination. 

There is an important issue when dealing with (near/non-) complete non-transitivity in customizable games: in some games the rating of the individual items would be ok, but the combination of some of the specific items should have a far higher value than the sum of the separate items. This especially happens in Customizable / Collectable Card Games where two individual cards are not too strong, but as combo winning.

Good examples on non-transitivity in general are the kid's game Spacix (click to see more examples based on Spacix) and "Hungry troll and the Gobbo's".

This is how the cards look:

 

In all cases the active player calls a attribute. The player with the highest score on the attribute wins the round and collects the cards. The player with the most cards in the end wins the game. 

Using several different non-rancidity attributes in combination is typical ingredient of a good game. If you look at chess, Warhammer, many CCG's, they all use non-rancidity attributes in combination with variations. 

How to deal with non-transitivity?

It's nearly impossible to create a fun game with full transitivity, if you don't make sure that the rules make a difference. The most common way to balance non-transitivity is to rate the cards in power and to set a limit number of total power. This is done in for instance Warhammer and MLB Showdown.

Non-Linearity

Games, in general, should not be linear. Progression of the game should not happen according a fixed story. This is however a general note, some games really go nicely with a story line (e.g. Knezia's Lord of the Rings).

Interactive vs. passive games

In interactive game, the players (can/must) react to moves of the other players. There reactions, on their turn, lead to new actions / situations. Most games are interactive (obviously) so there is no reason to go into deep discussion here, there are however lots of (successful) games with only limited interaction, such as Mastermind, other puzzle based games and lots of children's racing games ('throw a dice, move x forward, who first reaches the endpoint wins'). Nevertheless, interaction is considered a basic (and main) ingredient for a successful game. 

In many (poor) games you will see 'mandatory' interaction, whereas there is no need for interaction at all (e.g. many children's games such Mother Goose), but has been introduced for commercial reasons. Even worse, the interaction is irritating in some cases.

Conflict vs. cooperation games

Lots of games are of the full conflict type, you have to battle you opponent to win (Chess, Go, etc.). Over the last few decades however numerous cooperation games have been introduced, especially in the multi-player environment, where you cannot win without cooperation of some kind: you have to work together with your opponent in some way in order to win. Typical examples are Siedler (Settlers), Diplomacy (click here to find an mathematical description of the gaming theory behind diplomacy) and other trade games. Cooperation games are usually games where players have different goals.  Some typical conflict multi-player games also allow cooperation (e.g. Risk under house rules). Cooperation games were not very popular, but apparently nowadays the designers have found mechanics that appeal to the public. 

A very good cooperation game is 'Lord of the Rings' by Reiner (Sophisticated Games) Knizia. Although there can only be one winner, players must cooperate or they will loose all. Although 'loosing all' is in general a bad game mechanic, in this case is nearly perfect interwoven with the cooperation concept.

Zero / Constant sum games

Constant sum games are games where the total outcome of the game is set, concrete money/points/anything is reallocated between the players: if one wins x points, the sum of points of the other players would be -x. Consider a situation where the objective is gain x% market share. The absolute maximum is therefor 100%. This means that if one player gains 1%, at least one player will lose market dominance. More general, an advantage for one player means an equal loss to other players, the sum will always be the same. These types of mechanics can be found in economic simulations. There are many interesting economic and mathematic theories on equilibrium within constant sum games (Pareto efficient etc.).  Become a econometric student!

Most economic games contain elements of Zero-Sum concepts. Actually, in theory most games contain Zero-Sum games, as games are a restricted representation. Although Monopoly has (in theory) unlimited money, there are only limited streets. And no matter how much you deal, the total number of street will always remain the same: you cannot build another street. 

Static vs. dynamic games

A dynamic game is game with changing circumstances during the game, as defined by the rules. A typical example is Axis&Allies where the Axis side has a strong advantage in the beginning of the game while the Allies have advantage in the end game. In a static game the rules for every one stay the same during the game. In dynamic games, the situations of the players changes over time, due to outside influences (the rules, that is). 

Open vs closed games

In open games, players see each others 'playing parts', whether that would be money, stocks, reserves, etc. In a closed game, more or less information regarding the position of your opponents is not revealed to you. 

bulletConsider a game of chess, you know exactly what the situation of your opponenent is. You could even think out his strategy.
bulletConsider a game is risk, although you can perfectly over view the batllefiel, some information is hidden to you (country cards, goal card)
bulletConsider a game of aquire, where share's and money of your opponents is hidden, especially when playing in a multiplayer environment, you haven't a clue who are you up to.
bulletConsider a game of poker, the only information you have on your players opponent hand is his way of behaving, your hand and your knowledge on statistics.

Ergo, in a closed game, information about your oppenent is nearly available, only based on the information you might gather (and memorize!), induction/deduction, behaviour and statistics.

Evolving games

In most games, everything is clearly defined up until the start of a game. A typical example is Chess, whereas you start from a given situation. Tic-Tac-Toe is another example.  A typical example of an evolving game is Magic the Gathering and other CCG's. Whatever strategy or deck you may come up with, WotC (the publishers) may radically change the situation by either changing the rules or publishing new cards. The fun part here is that the limit of the game is no longer fixed. While playing the game, the outside world may change the game you are playing (compare this to Game Theory games, whereas government may change taxes / laws (unexpected) and thus changing the complete environment of the game). An evolving  game is a game that can be played for a while under certain rules (a defined game), but is affected by changes in rules by the outside world. 

Although this looks interesting, a lot of players get frustrated as rules keep changing. Also, especially in collectable games, high paid models/cards may become worthless as their use in the game diminishes. Typical examples are Magic The Gathering and GameWorkshop Games, where each new edition usually upsets the 'old' players.  

Board building games

Board building games are games, where players put together their own playfield while playing, also know as Tile-laying-games. This concept is often used by CCG's such as Middle Earth and Star Wars, the German Style games (Siedler, Tikal, etc.) and games like 'Pipedreams/Plumber'. Some of these games, esp. card games such as Middle Earth, are also called 'traveling' games: as you play to set up the route you are going and that is affecting your and your opponents game play. The fun part is that your strategy has limited scope since you have ot anticipate on the tiles that are to be layed and you are not the only one who can influence that part. Other games where tiles are being layed are Warhammer Quest and many discovery games (Tikal).

Racing Games

A lot of games are build around this mechanism, especially kids game. The object: get to the endpoint as soon as possible and avoid trouble. Usually a dice determines speed. There are but a few racing games that can be called adult games (Formula De is a good example). A lot of games combine this mechanism with others mechanisms (e.g. Monopoly: buy the streets asap and then the real game of negotiating actually starts). Lots of 'cheap' games come with this mechanism as main mechanism, usually with a few dices too. Games that are only supported by the racing mechanism as main mechanism become boring very fast (especially for adults).

Roleplaying

One of the thing to keep in mind is that players want to play certain role. Even more, players want to switch roles. Ever played Risk? Then you know there are agressive players, cautious players, defenders, peacekeepers, etc. It amazes me, especially when you play with mixed sexes how pleople take a certain role (and switch it). Even in cooperative games (like pictionary) you have creative roles, leading roles, operational roles, etc.. Keep in mind that good game gives room to various roles. I know this sounds like 'open doors', but hey, look around in the game market and look at all the loosing games. As already said before, in games people sometimes want to try and play different roles (as part of a learing aspect?), just for variation. Some things to keep in kind:

bulletagressiveness: can the player play agressively?
bulletluck: can the player be lucky, take chances?
bulletcooperation: can players work together? 

Scenario games

A number of games are build to follow a certain scenario. Typical examples are many wargames (D-Day scenerio's etc.).  Some of these games actually follow various scenario's. You can find this in many (war) computer games. In boardgames mainly wargames use this mechanic. Warhammer as a typical example has many scenario's available. 

In some cases a gamemaster is the only one who controls the scenario, while the other players are not aware of the progression of the scenario. In addition, Dragons & Dungeon games purely work on scenerio's. HeroQuest, Warhammer Quest and of Course D&D itself are typical examples. These type of games also allow the player to come up with own scenario's.

As this is not new though, it's interesting to see how for instance Tolkien-alike games work. Many of these games follow the famous book of 'Lord of the Ring' by Tolkien (e.g. the recent LotR game by Knizia), whereas you play a 'story'.  

Note that scenario playing is not actually a mechanic, it's more a theme-thing

 

Complexity of the game

The complexity of the game is one of the major challenges. Complexity does not neccesarily mean complex rulings. A game like 'Go' has very limited rulings, nevertheless it's pretty complex in playing. A typical family game in this genre is Aquire: can be taught in less than 10 minutes, but remains challenging: you cannot get a grip on it by simply applying some rules. If you look at tic-tac-toe, it looks like a challenging game the first time you played that game. It should take you less then 10 games to figure out the one-and-only tactic. So apparently, any good game should have complexity, disabling the player to overlook all the consequenses of his choices. The choices / tactics / strategies / allocation of player should have a level of high diversity. In conclusion, one choice should influence the game at many levels (tactical, strategical, short term, long term, etc.) in a way it's consequenses cannot be overlooked competely, that is what makes a game complex and thus challenging. Nevertheless, as games may be targetted at certain markets (e.g. kids games) complexity varies a lot.

A lot of non-transitivity usually means a complex game (e.g. compare Chess, where all individual pieces have their own advantages / disadvantages).

What makes a game really poor is, if the game is very simple in itself and where complexity is added by chance (i'm actually wondering if you can call that complexity...).

Boys vs Girls Games

Just an observation, did you ever notice a 'playing' scene, where Girls/Women where involved, esp. in majority? Gaming mainly is a Boys/Men's thing. G/W do play games, but in general other types of games than B/M. There are but a few games that appear to be challenging to G/W, just to mention a few: Settlers, Scrabble, Pictionary, etc. 

What strikes me is that games that attract both sexes all social games and/or cooperation games, usually non-strategic games. G/W's that like Risk, Chess and Wargames (Games Workshop, Axis&Allies, etc.) in general, I do not seem to know them. The same goes for games like Magic, Aquire, etc. Maybe it's that Venus/Mars thing, but I guess you could become pretty rich if you were able to develop a game that woul attract both sexes. The good news would be, when something attracts G/W's, B/M are usually nearby.

A few exeptions I've noticed are Siedler (both board/card game) and some of the standard family games (Scrabble), but usually the G/W's play for social reasons, while the B/M play to win (and keep winning). A game like Set! is also very good example of a B/M/G/W game. Another positive exception seems to be Brigde.

G/W girls tend to be more 'social' games (beating up eachother is out of the question). In addition, G/W games are usually not the games like 'me-against-you', but more like proving the winner is the best, whoever would be the opponent (Set!, Trivial Pusuit, etc.). Another sexist remark from my side: G/W specific like games where they can talk a lot (grin).

General guidelines for development

In general, keep the following rules in mind

bulletKeep it simple
bulletUse intuitive mechanics
bulletUse intuitive models and symbols/descriptions
bulletDefine the goals clearly
bulletMake the game easy to learn, hard to master
bulletAvoid exceptions on the general rulings
bulletThe game should have several 'thrills' / 'layers'
bulletMinimize the number of attributes
bulletCheck the time-span of playing (< 1 hour)
bulletMind the theme!
bulletMIND THE LOOK AND FEEL!

If you look at all the great games, they almost all obey these rules: Chess, Dames, Go, most common card games (Poker!), etc. I have seen a few games that were so hard to learn and so inconsistent in their ruling (lots of contradictionary exceptions!), I sold those game off before actually playing (too bad, I really regret that, because I sold off one of the lousiest games ever, forgetting to write down its name).

Although some games require complicated rulings, because the game is targeted at a specific group (e.g. war games), always try avoid rulings that require more than 2 A4's. Also include lots of examples. New CCG's nowadays start of with a fixed starter set that shows the first few draws and actions. MLB Showdown is good example of how a game can be taught to new players.

Also keep in mind that a good game should have several thrills / layers. Just throwing dice and comparing the outcome is not good enough. A good game combines several mechanics including the option for (nearly) infinite strategies on how to use / combine those different mechanics. In case of dices, if you have throw enough dices, you can predict the outcome and set a strategy to it (upfront).

As you are developing a simulation, you will be tempted to enter as much attributes as possible. You may want to add the weather, the price of the Dollar vs. Euro, the psychological state of the characters and many other very interesting variables. The main issue is to limit the number of attributes to a few basic ones. Taking you back to my econometric background: the key factor of a great model is limiting the number of key variables and their maximum contribution to the model. If you can, cluster as much variables as you can to a single one (e.g. economic situation, general state of the character). Check how critical the different variables/mechanics are to the fun of the game. If they are not critical, eliminate them or cluster them into one single variable / mechanic. In Econometric this has a name called Factor-analysis, keep it in mind. 

Oh, you are thinking that your game is a blockbuster? Get a checklist on how a game can be successfully:

bulletis it build on existing games / concepts (how many scrabble look-alikes can a human stand?)?
bulletDoes the game have a great name? That is remembered easily? That reflects the heart of the game? That appeals to the gamers fantasy?
bulletDo the game elements challenge the gamers fantasy, will to play, will to win?
bulletDid you have a test group? Who will alpha/beta test your game? Do you have methods and tools to measure and improve your game? How do you guarantee a non-broken game?
bulletDo you have anyone with a mathematical background around that can tell you about chances, lockups and broken situations?

For more information see the building block section.