Neb. Rev. Stat. §§ 25-901
The defendant in an action for the recovery of money only may, at any time before the trial, serve upon the plaintiff or the plaintiff's attorney an offer in writing to allow judgment to be taken against the defendant for the sum specified therein. If the plaintiff accepts the offer and gives notice thereof to the defendant or the defendant's attorney, within five days after the offer was served, the offer and an affidavit that the notice of acceptance was delivered in the time limited may be filed by the plaintiff or the defendant may file the acceptance, with a copy of the offer verified by affidavit. In either case, the offer and acceptance shall be entered upon the record, and judgment shall be rendered accordingly. If the notice of acceptance is not given in the period limited, the offer shall be deemed withdrawn and shall not be given in evidence or mentioned on the trial. If the plaintiff fails to obtain judgment for more than was offered by the defendant, the plaintiff shall pay the defendant's cost from the time of the offer.
Neb. Rev. Stat. §§ 25-901