what are some important character developments in chapter 4?

Countless times throughout the story, Vladek's resourcefulness and quick mind help him to survive and to provide for is wife. However, these traits are ultimately not enough to save his life. However intelligent and resourceful Vladek is, his survival ultimately depends a great deal on luck. This is especially true as the situation deteriorates even further, but instances of luck can also be found in these early chapters. An excellent example of this is when he is caught carrying the black market sugar. Though he thinks quickly and devises a lie that fools the German soldiers, his survival in that situation was by no means assured; it was dependent upon the mood and intelligence of the soldiers and the reaction of the person to whom he delivered the sugar. Vladek's intelligence improved the odds in his favor, but his survival was nevertheless dependent on a roll of the dice.