A version of this article first appeared in the June/July 2009 issue of Game Developer magazine.

A lot of explanations have been given for the explosion of poker in the early part of this decade.  Factors cited have included in the rise of online poker, the surprise victory of amateur Chris Moneymaker in the 2003 World Series of Poker, the success of the movie Rounders, and even the NHL lockout which left ESPN scrambling for cheap content to show in winter months.  I’d like to propose one additional reason: the rise of a superior form of poker.

For decades, when you saw a game of poker being played in a movie, what you saw being played was probably five-card draw – all players are dealt a hand, may replace some cards in a single draw, and then reveal, with opportunities to bid along the way.  The dirty secret of five-card draw is that it’s not a very good strategy game.  Players have little information to base their strategy on – their own hand, how many cards their opponents draw, and how nervous their opponents seem.  Draw poker is entirely about bluffing and luck.  This makes for classic cinema, but from a gameplay perspective, it’s hardcore and fairly unsatisfying to play.

But that’s not what they play on ESPN2 at 2 AM.  As poker exploded, Texas Hold’em was the game of choice.  In Texas Hold’em, all players must make a five-card hand out of two cards they have privately (their ‘hole’ cards) and five others that everyone shares.  Suddenly, you have very good information about what your opponents can do – three-fifths of their final hand is on the table, after all.  The odds of victory and defeat become a math problem instead of one of pure luck.

Bluffing is still important, but it isn’t the dominant path to victory.  Strategy is – and this strategy is created by the amount of information given to the player.  As game designers, we must understand that the level of information that we give players affects how strategic or tactical our games are.

 Introducing Tactical Transparency

When discussing games, the term board state refers to the current state of variables in the game.  In chess, the board state is the location of all of the pieces.  In Poker or Magic the Gathering, the board state is what’s on the table as well as in the player’s hand.  In a First Person Shooter, it would be the health, weapons and ammo available to both you and your opponent.

Tactical transparency is a description of how much of the board state is exposed to each player.  In classic chess or checkers, the board state is entirely exposed to both players.  Every piece of information a checkers player could use is in front of him.   Surprises are failures on the part of the player to foresee all possible outcomes of the current board state.  The information available to the player is perfect.

Imperfect Information

Of course, most games do not expose their entire board state. Many successful games shroud some of the board state, force players to adapt tactically as the game unfolds.  In many cases, however, you offer them hints.  These hints are imperfect information that allow the players to make informed decisions without necessarily ensuring they will make the right one – or even that a winning move exists.

Blackjack is not perfectly tactically transparent – the dealer’s second card is hidden – and the game would be quite broken if it was.  That being said, the player knows two key pieces of information about the dealer’s board state: the dealer’s top card, and that the dealer is bound by the rules on when he can hit or stay.  These two bits of information are enough that a smart player playing optimally can very nearly erase the house edge in the game.

In Magic: the Gathering, you normally have no idea what cards your opponent has in his hand.  However, you do know what resources are available to him – primarily the mana base he has on the table. If he has nothing but red mana, you know that he could cast direct damage spells like Lightning Bolt and Disintegrate.  Even more importantly, you know what he can’t do – he can’t, for example, cast a Counterspell, as those require blue mana.  This information allows the player to build a battle plan.

Game resources are often a good way for a designer to create imperfect information.  If a missile goes whistling over your head in Quake 2, you know your opponent has a rocket launcher, which is useful information.  You don’t know how much ammo he has, but you do know that a player can’t carry more than 50 rockets.  Sometimes, imperfect information can be made more perfect if the player is willing to track it.  The resources that a player has drawn in Settlers of Catan are kept hidden, but if you’re willing to track them as their distributed and spent, you can gain a pretty good idea of an opponent’s capabilities.

Tactical Transparency in Non-Strategy Games

The concept of tactical transparency is most strongly adhered to in turn-based strategy games, of course, as fans of the genre value information highly.  However, even games well outside of the strategy genre can benefit from the philosophy.  One example is the ‘light meter’ in games like Thief or Splinter Cell. 

The light meter is a UI element that shows if the player is successfully hiding in the shadows and how likely the AI is going to detect the player.  I’m sure that some designer on the Thief team tried to argue that having an extra GUI element displaying this information was unrealistic and immersion-breaking.  But the opposite is true – by giving the player perfect information about how visible the game thinks the player is, the player learns much quicker what is actually good stealth and what is not, and ceases to worry about external forces that could affect their perceptions: camera angle, monitor glare, or glitches in the game’s lighting algorithm.  The player’s focus may be on an artificial UI element, but he is much deeper into the stealth experience as a result.

Almost every bad boss creature I can think of is ultimately a failure of tactical transparency.  Boss creatures tend to be about megahits from the creature, or moments of unique vulnerability.  In bad boss fights, these aren’t communicated well to the user.  When the player defeats such a creature, he feels that it is more due to luck than skill.  And while winning due to luck is fun, it doesn’t nearly match the sense of mastery that a victory based on skill or tactics provides.

Tactical transparency can affect even basic decisions a player has to make.  In most games with a heightfield, there is an angle at which the terrain is simply too steep to climb – let’s say 60 degrees.  The problem is that slopes at 59 and 61 degrees look identical.  Trying to climb both will make the world feel wildly inconsistent.

To ensure there is no ambiguity, worldbuilders should painstakingly ensure that steep terrain is clearly visually different, such as being painted with a different texture. Slopes near the non-climbable threshold should be forbidden (i.e. no slopes between 50 and 70 degrees).  Designers may argue that it limits their freedom create immersive environments.  However, few worldbuilding decisions breaks immersion more than hitting an unclimbable slope the player wasn’t expecting while he’s desperately running for his life.

Case Study: Classes in MMOs

One of the classic design debates is whether MMOs should have rigid classes, or whether players should be able to combine skills with freedom.  While there are good arguments on both sides, one interesting way to look at the debate is to see how tactical transparency affects PvP.

In Warhammer: Age of Reckoning, if you see a Witch Elf, you know her capabilities – she can stealth, debuff via poisons and deadly kisses, and do a lot of burst damage. She also is a lot less deadly kept at range.  This information is still imperfect: you don’t know her mastery path, her gearset or any of the other ways she’s fine-tuned her character spec.  Still, if you run across a Witch Elf, the strategy and tactics you employ is going to be very different than if you stumble across a Sorceress.

If you couldn’t tell a Witch Elf from a Sorceress, strategy becomes impossible until combat is engaged and you see what abilities your opponent is using – and then the decisions that you’re making are purely twitch-speed tactical.  In a pure classless environment –i.e. any character can have any combination of abilities – strategy disappears.  You know nothing about the combat capabilities of your opponent, and cannot proactively make adjustments to deal with them.  Without good information to base tactical decisions on, most players will devolve their tactics to a single abilities rotation that works the majority of the time.

This is not to say that classes are the right answer.  But advocates of classless systems need to understand that if they don’t increase tactical transparency in the absence of what classes have to offer, PvP Tactics may be throttled in the crib.

Information Wants to Be Free

Too many designers try to keep too much hidden.  Many are in love with the idea of surprising the players.  The problem is that such surprises often feels unfair and capricious and forces the player in a pattern of trial and error to learn. Perhaps if we called this pattern ‘die-and-quickload’, designers will finally understand how unfun it is.

Another culprit is the urge to hide numbers and information, to prevent players from becoming overloaded with information.  But hiding the numbers is the wrong approach – making the player choose between a ‘strong’ upgrade and a ‘great’ upgrade is much more frustrating than making him choose between bumping a stat +6 vs. +8.  Rather than hide this information, designers should expose it, while striving to make the mechanics as simple as possible, so that you don’t have to be a member of Mensa to understand the tradeoffs you are being asked to make.

Finding the right balance of tactical transparency for your game is a balancing act.  If a game requires no tactics or strategy and success is guaranteed, then it risks becoming a forgettable exercise in button mashing.  If a game awards victory only in limited conditions, but does not give players enough information to strive towards that condition, the game becomes an exercise in luck, as is the case in Five Card Draw.  How much should you expose?  This will vary from game to game, but in my experience, the designer should err on the side of more.  Sometimes it may seem like you’re exposing too much, but let’s not forget, chess is considered the greatest game of all time — and they show everything.