Based on the Dungeons & Dragons 5e system of play, which Character Class seems to have the least chance of survival in a Dungeons & Dragons 5e campaign?
Well 5e is remarkably balanced. All of the classes are pretty good unlike previous editions. A person has to work at making any of the classes weak. The original Ranger class was very weak but the revised Ranger can hold their own with any class.
My best answer would be the wizard I suppose. They end up being powerhouses but are very vulnerable early in the game. If not kept out of danger their low armor class and hit points can spell their doom.