The NBA coach's challenge is not a general right to re-officiate a play. It is limited to specific called events, must be initiated through the required procedure, and cannot be used to challenge most non-calls.
The main challenge categories are personal fouls called on the challenging team, out-of-bounds calls that awarded possession to the other team, and called goaltending or basket interference. A coach cannot use the challenge just because the bench disliked the whole sequence.
A missed travel, missed foul, possible carry, double dribble, or uncalled three-second violation is generally not independently challengeable. The replay can sometimes review related matters once a proper challenge is triggered, but the challenge has to start from an allowed called event.
In the last two minutes of the fourth quarter and the last two minutes of overtime, certain replay areas are handled by official triggers rather than by a coach's challenge. Goaltending and basket-interference review has special late-game treatment under NBA replay rules.
A team must have a timeout to challenge. Because timeouts are strategically valuable, coaches have to decide whether the potential correction is worth the cost and whether the timing of the game makes the challenge more important. The head coach must also make the replay signal during the required interaction with the officials when the timeout is requested; waiting until the timeout discussion is over can make an otherwise eligible call too late to challenge.
Replay needs clear and conclusive visual evidence to overturn the challenged call. For a foul challenge, success generally requires removing the foul from the player originally charged; merely changing a shooting foul to a non-shooting foul while leaving it on that player does not make the challenge successful. Out-of-bounds and goaltending challenges have similarly defined outcomes. This distinction matters because challenge rights and timeout treatment depend on the formal result, not simply on whether replay changed some detail.
Every team begins with one challenge. If that first challenge is successful, the team keeps the timeout associated with it in ordinary circumstances and earns a second challenge. A second challenge does not generate a third, and the team does not retain the timeout used to initiate that second review even if it wins. Mandatory-timeout situations can also affect which team is charged, so the scoreboard may not show the simple timeout result viewers expect.