“Game coaching” requires coaches to be able to adjust to what is happening in the game, regardless of the “game plan” that was prepared prior to the game. Coaches may need to react to:

The opponents adopting different tactics than anticipated (including match ups as well as offensive and defensive patterns of play);
Players getting in foul trouble (either an opponent or their own team);
The opponent having an “unanswered scoring run” (i.e. the opponent scoring a number of possessions in a row without the team scoring);
The opponent successfully countering the tactics that the coach prepared.

A time-out (a 1 minute opportunity to speak with the team) is perhaps the best opportunity to change tactics, although the coach has a limited number to use during the game. To be most effective, the coach should limit what they say at a time out to two or three key things.

Because a timeout is an extended break in play it can be used to break the “momentum” of a game, even if the coach does not change any specific tactics. Indeed, the timeout may be used to reaffirm the tactics to be used. Many coaches prefer to retain the time outs until later in the half, particularly in the second half so that they can be used to give specific instruction towards the end of the game. If a team that has to inbound the ball (e.g. after an opponent scores) calls a timeout in the last two minutes, the ball is actually thrown in from half way.

However, more commonly coaches make most changes during play not at a time out:

Making a substitution;
Changing team tactics (e.g. changing from zone defence to man to man defence);
Changing individual tactics (e.g. changing from fronting a low post player to double teaming the post player).

Communicating the change can be done through a substitution, by speaking to a player during a break (e.g. speaking to the point guard while foul shots are being taken) or using predetermined signals (e.g. hand signals such as a fist or naming different tactics by number of colour).

The tempo at which the game is played is often a good indicator of which team is controlling the game. Most teams have a preference for the tempo at which the game is played, although champion teams may have a preference but are usually able to play successfully at another tempo.

Influencing the tempo of a game is often the purpose behind a substitution, a change in tactics or a time-out and some coaches will include specific rules in their game plan aimed at influencing the tempo of a game, for example:

Not taking a shot from outside the key unless the ball has first been inside the key (either by a pass or dribble) – this tends to slow the tempo of the game;
Using a certain offensive structure or play if the opponent has scored three unanswered baskets – this is often used to slow the tempo;
Designating who is to inbound the ball after a score – this can quicken the tempo as that player will move straight to the ball;
Team rule as to which players can shoot quickly in transition (e.g. a 3 point shot) – this may quicken the tempo when they are on the floor and slow the tempo when other players are on the floor;
Using full court pressure after taking free throws – this can quicken the tempo.

Substitutions can also affect the tempo if the game style is changed according to which players are on the floor. For example, a team may prefer a half court offence (slower tempo) when their starting centre is on the floor but play a quicker up-tempo game when a substitution is made (if the replacement centre is quicker).

Similarly, one point guard on the team may be stronger at pushing the ball and playing up-tempo, where another is better suited to a half court game.