Start the game with the "-w" command line parameter to run it in a window on the desktop.
Successfully complete the game to get the Horadaric Cube. Then, obtain "Wert's Leg" in Tristram (where you go to rescue Deckhard Cain). Go to the northwest part of the town and search the boy's body. Place both Wert's leg and a Tome of Town Portal in the Horadaric Cube, and it will open a portal to a hidden level filled with axe carrying cows. Do not go through the portal until you are over level 35 because the cows are quite numerous and strong.
When you get an item and want to imbue and are worried about the outcome, copy the "Save" folder from the Diablo 2 folder to the desktop or any other location. Start your game and imbue. If you do not like what happened, save the game and exit. You will now be at the main menu again. Press [Alt] + [Tab] and copy the save folder back to its original location. Then click "Single Player Game" and start. You have another chance to imbue the item. Repeat this until you get the desired effect.
Save and exit the game after dying. Restart the game, and your corpse will be in town, allowing you to retrieve your possessions.
Press [Esc] when facing imminent death, then save and exit the game. Load the game again to start in town, where you can buy weapons, life, etc.
Travel past the Blood Moor and look for a cave. The cave has two levels, with a golden chest somewhere at the second level. Inside are usually health potions, mana potions, scrolls of town portal or identify, unidentified weapons and armor, and sometimes even a rare item that can be sold for a great deal of money. If you identify the item and it is something that you do not want, sell it. Save and exit the game. The next time the game is loaded, the chest will still be there with different items. This can be done as many times as needed.
Identify or repair items before selling them.
Cast a Town Portal from a safe location, then take the portal into town. Use the waypoint system and run to get back to your last location. This allows you to use the portal to go back into town an unlimited number of times as long as you do not use it from town to return to where you were previously.
Note: This trick only works in an Open Battlenet game, as the characters need to be saved on your computer. This trick also requires two computers with two copies of Diablo 2. Get the items to be duplicated. Copy the "Save" folder from the Diablo 2 folder of that computer and paste it on your desktop. Go online with both computers and meet in a game. Give the items to be duplicated to the second computer, then save and exit. Press [Alt] + Tab] on the first computer to switch to Windows and copy the "Save" folder from your desktop back to its original location, overwriting its current contents. Return and join the other computer in the game. You will now have all your original items and the other computer will have a copy of them. Note: This does not work with the +1 Skill book from Act 2, as you are only allowed to do it once.
Note: This trick also only works in an Open Battlenet game. Take the item to be duplicated and place it in your inventory. Then, save and exit the game. Next, come back to the game or join a different one. Drop the item you want to duplicate. Make a note of the game name and password, then sign off of your ISP -- do not save and quit the game. Have another person in the game keep it open while you are logged off. Sign back on to your ISP, go back into the game, and pick the item that you dropped. It will also still be in your inventory, so you now have two copies of that item.