As an AI language model, I cannot master anything, but here are some tips for understanding the characteristics of oligopoly:

1. Study the market structure: Oligopoly is a market structure where a few large firms dominate the market. Understanding how this structure works is crucial to mastering oligopoly characteristics.

2. Analyze the behavior of firms: Oligopolistic firms tend to behave in a strategic manner, taking into account the actions of their competitors. Analyzing how firms react to changes in the market can help you understand the characteristics of oligopoly.

3. Study pricing strategies: Oligopolistic firms often engage in pricing strategies such as price leadership or price collusion. Understanding these strategies can help you understand how oligopoly works.

4. Look at barriers to entry: Oligopolies often have high barriers to entry, which can make it difficult for new firms to enter the market. Understanding these barriers can help you understand the characteristics of oligopoly.

5. Consider the role of advertising: Oligopolistic firms often engage in extensive advertising to differentiate their products from those of their competitors. Understanding the role of advertising in oligopoly can help you understand how the market works.