OT Texas Scramble Rules
Normally, 4 person teams play four balls, one ball per person, but with each shot coming from the same spot i.e. the best of the four drives is chosen and all four team members then hit from that spot, and so on until the ball is holed.
 Four drives of each member of the team must be used during the course of the round i.e. at least four drives hit by player A, four by player B, and so on.

Stableford handicaps are used in play, with a fraction of the total handicaps of the team members serving as one handicap for the team:

for a 2 person team the handicaps of the 2 players are added and divided by 4
for a 3 person team the handicaps of the 3 players are added and divided by 6
for a 4 person team the handicaps of the 4 players are added and divided by 8

Assuming the scramble is based on 4 persons per team, if a team comprises only 3 players, then each of the three players will take two shots (by rotation) to ensure that the same number of shots are played by a 3 person team as a 4 person team.