Full and fair opportunity refers to the legal standard ensuring that a party has had a genuine chance to litigate an issue before a court, which is essential for the application of issue preclusion. This concept is fundamental in determining whether a party can be barred from relitigating issues that have been previously decided, as it assesses whether they were given adequate notice and the chance to present their case effectively. Without this standard, the integrity of the legal process would be compromised, and parties might face unfair disadvantages in subsequent proceedings.