How to Play Dungeon
The Dungeon Players' Guide
How To Enter Commands
You play Dungeon using words.
If you're using our GUIs, enter commands into the text box at the very bottom of the screen. That's the long, thin white area which is below everything else. Here's a (fuzzy) screen shot which shows it (sort of). See the text highlighted in blue at the bottom? (It says "chat have you seen all the new stuff?") That's the command field. Enter your commands there and hit enter/return. If you're using your favorite MUD client — do what you always do. 😊
You'll want to enter commands in the imperative mood. You're giving commands, after all. Your commands will begin with a verb, and end with the direct object, as, "look at the shoes"
Keeping our emulation true to the original, Dungeon does not have a comprehensive natural language parser. Dungeon's parser may feel arbitrary if you're used to TriadCity. For example, you can't type "put the <thing> into the <thing>". It has to be "put the <thing> in the <thing>" — "into" isn't recognized. If you find yourself struggling, try variations on your syntax. Part of the puzzle of the original is simply getting the commands sussed.
Fortunately there aren't that many. Here's the complete Command Reference.