Every position has both positional ("theory") aspects and tactical aspects.
Positional aspects would include the various imbalances in the position: pawn structure, space, center control, knights-vs-bishops, and pretty much anything else that would generally fall under the category "theory" .
Tactical aspects are just what they sound like: tactics.
I move here, he moves here, and in 4 moves I win his bishop.
A positional game is one that is primarily dominated by positional aspects.
Of course, every game has aspects of both, but in positional games the theory is much more pronounced.
I hear the term "positional game" especially often in conjunction with a closed center - a game in which pawns occupy the center, so attacks have to be mounted on the flanks (sides of the board), usually with pawns rather than pieces.
These games tend to be slower and less intense; it is not uncommon for a player to spend half-a-dozen moves or more moving his knight to its optimal position before pushing a pawn one square.
Because of this, many players consider positional/closed-center games boring .
"Positional game" may also refer to a game where an early endgame was reached, causing most of the game to be dominated by endgame theory.
Tactical games , on the other hand, are dominated by tactics.
For example, see the Fried Liver Attack or the Danish Gambit , which always lead to very tactical games.
boardgames.stackexchange.com/users/175/BlueRaja - Danny Pflughoeft
“Tactics is knowing what to do when there is something to do.
Strategy is knowing what to do when there is nothing to do.”
– GM Savielly Tartakower (1887-1956) In a tactical game, you calculate on (material) profit.
In a positional game you perform careful actions to improve your position, without expecting large profit in the beginning.
In most cases a positional game ends in a situation with interesting tactical options.
The following are some (common sense) rules-of-thumb when playing a positional game: 1.
In an open game, a (good) bishop is usually a bit stronger than a knight.
In a closed game, the action-radius of bishops is reduced and knights become stronger.
2.
A doubled pawn is especially weak when isolated from other pawns.
3.
Try to trade 'bad' pieces.
4.
Try to rule the center and do not allow your opponent to rule the center.
5.
Attack where you dominate or have more influence.
6.
When you have a spatial advantage, do not trade pieces needlessly so that your opponent continuously needs to rearrange his pieces.
7.
Ideally, your bishop and pawns are complementary.
For instance, your bishop on a black field (g3) and your pawns on white (f3 or f5).
This covers a maximum of fields.
8.
First investigate on tactics, for instance by searching for possible checks or checkmates.
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A positional game in chess is one where you try to control the territory on the board.
Positional players develop pieces and go for king safety early, play for good pawn structure, and pay attention to how many squares their pieces control on the board.
The opposite of a positional game is a tactical game.
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A positional game is one in which you try to go for a better position, specifically control of key squares, particularly close to the center, or in the vicinity of the enemy king.
You often do this at the expense of other considerations in the game such as material.
Perhaps the best example is the queens gambit.
White offers black a queen bishop pawn (and some tactical chances).
If black accepts the pawn, white is likely to get a stronger center and the king side.
A century ago, it was considered bad for black to give white these positional advantages, but modern, particularly Russian players, have demonstrated that the material and tactical chances compensate for white's better position.
Another example is when you exchange a bishop for a knight to "double" your opponent's pawns.
Inflicting doubled pawns is a positional advantage, but some masters considered trading a bishop for a knight as "giving up the minor exchange" (on the theory that bishops were worth more than knights.)
boardgames.stackexchange.com/users/1344/Tom Au
In a positional game, the pieces remain in the game longer than tactical games and the middle-game
is the dominant part of the game.
Generally speaking, Positional players are more inclined to finish their games as a draw.
there are balanced advantages in the position: if one player controls the center, the other one might have possession of a Column with heavy pieces.
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What does it mean to have a positional game, or to play a positional game?What is the opposite?
What is a positional game in chess?
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<chess>
boardgames.stackexchange.com/questions/3234
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This is a game with a closed center, when pawns occupy the center. It could also be a game where the endgame is quickly reached. The pieces remain in the game longer than a a tactical game. A  positional game  is one that is primarily dominated by positional aspects.  A positional game is one in which pawns occupy the centre, so attacks have to be mounted on the flanks, usually with pawns rather than pieces.  A Positional game may also refer to a game where an early endgame was reached. In a positional game you perform careful actions to improve your position, without expecting large profit in the beginning. A positional game in chess is one where you try to control the territory on the board or go for a better position. 
In a positional game, the pieces remain in the game longer than tactical games and generally speaking, Positional players are more inclined to finish their games as a draw.  
A  positional game  is one that is primarily dominated by positional aspects.   A positional game is one in which pawns occupy the centre, so attacks have to be mounted on the flanks, usually with pawns rather than pieces.   A Positional game may also refer to a game where an early endgame was reached. In a positional game you perform careful actions to improve your position, without expecting large profit in the beginning. A positional game in chess is one where you try to control the territory on the board or go for a better position.  In a positional game, the pieces remain in the game longer than tactical games and generally speaking, Positional players are more inclined to finish their games as a draw.  