As the name implies, a general denial means that you are generally denying all the claims in the complaint, without going line by line and admitting or denying each statement. This option is frequently used when defendants do not want to commit to admitting or denying particular facts put forth in the complaint, especially at the early stage of the case. Essentially, a general denial gives no information to the plaintiff as to your strategy or position in the case, other than the fact that you are broadly disagreeing with the allegations.
However, a general denial is not an option in every case. You may only submit a general denial if the complaint was not verified, or if it is a "limited civil case," meaning the amount in controversy is $35,000 or less. Otherwise, an answer is the more appropriate response.
California Courts provide Form PLD-050 for general denials. Note the court's rules on the use of this form:
*A verified complaint means that the Plaintiff has sworn, under oath, that the allegations in the complaint are true. This verification can be found at the end of the complaint, or it may be a separate document.
As with an answer, you must provide your affirmative defenses with your general denial.