Classic
Classic mode is a playable mode of Demoncrawl without RPG elements, essentially making it default minesweeper. In Classic mode, the player has 1 life, objects do not spawn, heirlooms cannot be used and masteries cannot be selected. The inventory can be accessed through its hotkey, however since no items can be obtained in this mode, it is useless.
Creating a Classic mode Game
| Difficulty | Height | Width | Mines |
| Easy | 10 | 10 | 10 |
| Medium | 16 | 16 | 40 |
| Hard | 30 | 16 | 99 |
| Insane | 30 | 30 | 250 |
From the main menu, clicking on the red flag labeled "Classic" will open the classic mode creation UI. From this UI, this user can select the difficulty, skin and whether or not the board will require guessing. The skins are selected with left or right click, and can be scrolled through with the bar below it. Left clicking a skin will set it to the background, which changes the background image and the flag icon. Right clicking a skin sets it to the foreground, which will change the skin of the tiles before they are clicked. Under the skin selector is the difficulty selector. There are 4 preset difficulties: Easy, Medium, Hard, and Insane. Each difficulty changes the dimensions of the boards, as well as the number of mines. In addition to the preset difficulties, at the bottom of the UI there is an option of a custom made quest, where the player can define the dimensions or the stage and the number of mines. Any difficulty, preset or custom, can also be generated without necessary guesses by clicking on the "No guesses" checkbox. Clicking on the "Create Board" button will take the player to a board of the specified dimensions, although the actual values are generated after the first click.
Skins & Unlock Conditions
Most skins are unlocked by getting a high enough score on that stage while playing a specific quest, but a few of them have special requirements.
Note that 
Reef, 
Crypt, 
Wonder, 
Doom, and 
Mainframe are secret stages. They only have a 5% chance to appear in their normal quests. You can make them appear more easily in Beyond, but you can't get the skin by beating them there.
Trivia
- Clicking on the "Custom" box on the difficulty selector is not required to create a custom board,
- The custom setting on the difficulty selector can creates boards as small as 10 by 10 and as large as 100 by 100. Trying to input a number less/more than these limits will result in the min/max number being entered.
- The custom setting also allows for between 10 and 5000 mines to be added, however more than 5000 mines can be added to a stage by randomizing, as this number has a chance of being over 7000. If more mines are put on a board than it can hold, if more than the 10 minimum
- Beating a Classic board on a difficulty of Hard or Insane will grant the player the "Back in my day" achievement. This will happen even if "No guesses" mode is on.