What are the custom aspects of "The Lottery"?

Custom is at the epicenter of the story "The Lottery" because that is precisely what the village lottery is: a local custom and tradition for which no villager has detoured.

Because of this custom, one of the central themes of the story "The Lottery" is complaisance. It seems that the only thing that the villagers know about the lottery for certain is that there has always been one. 

The narrator explains how, when asked about the origins of this custom, the answers are never straight, nor is there a sequence of events that can be offered to explain the need for this horrific and inhumane practice. Some say that it was a ritual to procure that there would be crops that year. Others talked about "ritual chants," while others spoke of specific wardrobe used for it. These ritualistic behaviors are also an aspect of custom, particularly for a very ancient practice. 

Still, the villagers do not sway from engaging in such practice. The way that they see custom, however, has nothing to do with pride, individuality, or even identification. It seems as if, in this particular village, custom means simply the blind, brainwashed following of something for no reason at all. 

One more aspect of custom is that here are tools that enable the practice to take place. This paraphernalia used in the lottery embodies the mentality of the villagers. The black box, for example, is  presumably the original one. Due to time, the box has fallen apart, gotten worn out, and looks shabby. The idea of getting a new box has been discussed over and over, but nothing is ever done or resolved. It is as if the villagers are simply unable to move away from it; or from anything. As a result, the box,

 ....grew shabbier each year: by now it was no longer completely black but splintered badly along one side to show the original wood color, and in some places faded or stained.

Still, the villagers do nothing about it. 

Therefore, the custom aspects of the story include: The traditional practice in itself, the fact that this practice is followed by all, the fact that there is paraphernalia in place to enable it, and that there is a process that is followed by which the "winner" is picked. Unfortunately we know where the winner will end up: being stoned to death by the villagers before their supper time hits.