How could he enter the Dark Illusory World?

The way to enter the hidden level was to re-enter the game as an old character after the machine exploded. He had to choose the previous Level(Normal Level), or else there would be no Horadric Cube and Wirts Leg. Then, he would return to the original town of Rogue Encampment in Act I. Put the Wirt Leg and Tome of Town Portal into the Horadric Cube and combine them (press Transmute). A Portal leading to The Secret Cow Level appeared on the screen. This was the entrance to the hidden level! Tome of Town Porta Wirt Leg? How could he obtain these two items?

Answer 1

In order to enter the Diablo World, one would need some special skills and equipment.

A common method was to use magic tools such as dark magic books or dark runes to enter the illusory world. These items can be found in fantasy novels and usually contain all kinds of powerful magic that can help players play more powerful characters in the game.

Another way was to enter the Spectral World by playing a character in the Dark World, such as a Magician or a Thief. In the game, players could complete missions or take adventures to obtain the level and equipment of their characters so that they could better enter the illusory world.

The way to enter the Diablo world may vary from game to game, but no matter which method, players need to have enough skills and adventurous spirit to succeed in this dangerous and challenging world.