In Scripture we read many times of those who cast lots to seek and know the will of God in a particular matter. In fact, both God’s people and the world practiced casting lots for decision-making. Examples of the world would be the sailors on Jonah's ship (Jonah 1:7) who cast lots to determine who had brought God's wrath upon them and their ship. We also know of the Roman soldiers casting lots for Jesus’ garments (Matthew 27:35) at the foot of the cross. Casting lots eventually became a game for wagering. The practice of casting lots is actually mentioned some 70 times in the Old Testament and 7 times in the New Testament.
The tradition of casting lots occurs most often in connection with the division of the land under Joshua (Joshua chapters 14-21). Casting lots was a procedure that God instructed the Israelites to do several times in the book of Numbers (Num. 26:55; 34:13; 36:2). On a couple of occasions God allowed the Israelites to cast lots in order to determine His will in a given situation (Josh. 18:6-10; 1 Chronicles 24:5). Although it may not sound very sacred, lots were even cast for determining various offices and functions in the temple. (1 Chron. 24:5, 31; 25:8-9; 26:13-14). In the New Testament we read of the eleven apostles casting lots to determine who would replace Judas (Acts 1:26).
We are uncertain exactly what this looked like at the time although historically it would appear that a short stick in the mix of longer sticks was one way. Some used stones with one being marked differently from the rest. Even the rolling of dice was used as a means of making decisions or casting lots. A simplified version today in making a decision is to flip a coin.
Christians are nowhere instructed to use this practice in determining the will of God today. Some things to consider would be the fact that we have the complete Word of God. God has given us His complete revelation in order to know His will for our lives. God has also given believers the indwelling of His Holy Spirit to lead and guide them each and every day. Life does not have to be determined today by casting lots or flipping a coin. In Scripture, at one time, God chose to make His will clear to those that he wanted by utilizing this method of casting lots. It was a Biblical method that God chose at one time and it was also a method used outside of God by the world for decision-making and entertainment purposes. God has also gifted believers with the privilege of prayer in which believers can go directly to God and converse with Him in knowing His Will.
My summation is that it was indeed Biblical in its day and yet it is not for today since we have the completed Word of God, God’s indwelling Spirit, and the ministry of prayer to converse with God.