Section 3221. Offer to compromise

Except in a matrimonial action, at any
  time  not  later  than  ten  days before trial, any party against whom a
  claim is asserted, and against whom a separate judgment  may  be  taken,
  may  serve  upon  the  claimant  a written offer to allow judgment to be
  taken against him for a  sum  or  property  or  to  the  effect  therein
  specified,  with  costs  then accrued. If within ten days thereafter the
  claimant serves a written notice that he accepts the offer, either party
  may file the summons, complaint and offer, with proof of acceptance, and
  thereupon the clerk shall enter judgment accordingly.  If the  offer  is
  not accepted and the claimant fails to obtain a more favorable judgment,
  he  shall  not  recover  costs from the time of the offer, but shall pay
  costs from that time. An offer of judgment shall not be  made  known  to
  the jury.