An opening statement is generally the first occasion that the trier of fact (jury or judge) has to hear from a lawyer in a trial, aside possibly from questioning during voir dire.
Opening statements are, in theory, not allowed to be argumentative, or suggest the inferences that fact-finders should draw from the evidence they will hear.
Objections, though permissible during opening statements, are very unusual, and by professional courtesy are usually reserved only for egregious conduct.
Defendants are also allowed the option of delaying their opening statement until after the close of the prosecution or plaintiff's case.
[2] Specific tactics that can be incorporated in an opening statement are audio-visual elements, a clear overview of the coming presentation, and using deposition testimony to highlight key information they can expect of upcoming witnesses.