The term epic level refers to a very high level of play in the Dungeons & Dragons (D&D) fantasy role-playing game. Although such high-level play has existed in various forms in the game for decades, the term "epic level" was introduced in the game's third edition to refer to character levels that are beyond the standard leveling rules, or every level past 20th level. In the case of fourth edition, levels 21 through 30 fall into the Epic Tier level of play.
High-level play (above 20th level) was first introduced in the green-boxed Companion Set for the Basic Set in 1983. Although it was not specifically termed "epic", the rules covered play for characters as high as 25th level. It was quickly followed by the black-boxed Master Set (allowing play up to 36th level) and the gold-boxed Immortals Set (which detailed play beyond 36th level). During this time, what is now called the "First Edition" of the Advanced Dungeons & Dragons (AD&D) game, it had little support for characters above 20th level beyond rules for level advancement.
AD&D Second Edition also limited characters to 20th level, until late in the game's life. In 1996, TSR released Dungeon Master Option: High-Level Campaigns, which covered characters in any high-level game and included rules for characters of levels 21–30.
D&D Third Edition first coined the term "epic level" in 2001's Forgotten Realms Campaign Setting in order to account for the unusual strength of many of that setting's many most famous characters. These rules were quite simple, allowing a character to select from a short list of options with each epic level gained. With the subsequent release of the Epic Level Handbook in 2002, an entire system was introduced that allowed for infinite level advancement past 20th level. Each of the base classes was given an epic progression, as were some of the more popular prestige classes. The book introduced epic feats, epic prestige classes, and epic monsters to the game. In addition, it created an entirely new spell system to create epic spells, while still providing options for improving existing spellcasting into epic levels.