Action Castle is a tabletop roleplaying tribute to the classic Zork text-based computer game, and includes the basic rules for the Parsely system which involves the GM acting like a robot who is only capable of understanding limited number of commands. From the publisher's website:

> LOOK ACTION CASTLE

Parsely #1: Action Castle is the first in a new line of games called “Parsely Games.” Now you can “GO EAST” and “LIGHT LAMP” with the best of them. Canst thou master Action Castle before death claims thee? Parsely games are inspired by Ye Olde Text Parsers from days of yore, but substituting a live human for the computer parser. Parsely games are small, portable and fun for (almost) all occasions.

• Play them anywhere! On trips, in long lines, camping, at game cons…
  
• Play them with anyone! Young or old, expert or total n00b
  
• Play with a few friends or 100 random strangers at the same time