Most rule sets for mixed martial arts (MMA) competitions have evolved since the early days of Vale Tudo. As a result of health, legal, and moral concerns, many different rulesets were created, which give different countries and promotions very different tactics and strategies. Similarly, shoot wrestling organizations, such as Shooto, expanded their rulesets to integrate elements of Vale Tudo into their sport. However, for the most part, fighters accustomed to one rule set can easily acclimate to the others.