In baseball, if one team does not show up to play, the other won wins, by default.  In the law, once a defendant has been formally served with a lawsuit, he has a set amount of time in which to file an Answer or file a Motion to Dismiss.  If he does not, the plaintiff may ask the Court to enter his default.  In Superior Court, defendants are automatically entitled to a 10 day grace period.  In Federal District Court there is no grace period and the default can be entered the day following the deadline for filing the Answer.