Diablo I Walkthrough

Tristram
The player begins in Tristram, here the player finds several NPCs amongst whom is Ogden the Tavern Owner who introduces the player to the main storyline with the following dialogue:

"Thank goodness you've returned! Much has changed since you lived here, my friend. All was peaceful until the dark riders came and destroyed our village. Many were cut down where they stood, and those who took up arms were slain or dragged away to become slaves - or worse. The church at the edge of town has been desecrated and is being used for dark rituals. The screams that echo in the night are inhuman, but some of our townsfolk may yet survive. Follow the path that lies between my tavern and the blacksmith shop to find the church and save who you can."

After this the player will make his or her way towards the Cathedral where he will find the Wounded Townsman (if the Butcher Quest is available). Speaking with this NPC initiates the first quest, in which the players has to slay The Butcher. The wounded townsman has the following dialogue:

"Please, listen to me. The Archbishop Lazarus, he led us down here to find the lost prince. The bastard led us into a trap! Now everyone is dead... Killed by a demon he called the Butcher. Avenge us! Find this Butcher and slay him so that our souls may finally rest..."



The Cathedral/Dungeon
The Cathedral-style Dungeon covers the first 4 levels of the Tristram Cathedral. This style features grey stone walls, mostly decorated with arches and the floor is made up of brown stones. Throughout these levels a lot of sarcophagi can be found, containing either treasure or hidden monsters. These levels contain numerous shrines and libraries where players can learn new spells.
 * Level 1
 * Level 2
 * Level 3
 * Level 4



The Catacombs
The Catacombs have a somewhat similar style to the Cathedral, though it seems more ancient and the atmosphere is already a lot darker. There are still shrines and libraries, although fewer. Goat Shrines also appear, producing random, cryptic effects when used. The Catacombs span from Level 5 to Level 8:
 * Level 5
 * Level 6
 * Level 7
 * Level 8



The Caves
The design of the Caves is clearly not man-made unlike that of the Cathedral and Catacombs. It features open areas cut through rock which streams of lava flows. The player is usually exposed to enemy fire from many sides. Some monsters are capable of opening doors. There are usually no shrines (although on rare occations Goat Shrines and Cauldrons might spawn). The Caves feature levels 9 to 12:
 * Level 9
 * Level 10
 * Level 11
 * Level 12



The Hell
These levels' architecture made out of flesh, blood and bones and of pure Hell feature larger open areas and hordes of the game's toughest monsters. Cauldrons can be encountered here - they produce a random cryptic shrine effect when used (not recommended to touch though). This region is inhabited by the toughest of all monsters, though it also offers the best odds for finding good  and  items.
 * Level 13
 * Level 14
 * Level 15
 * Level 16