I'd like to give a shoutout for our graphical implementation of Ruby Warrior if I may :)
I did have to Google for ruby tutorials to figure out things like instance variables and I'm sure somebody who has no prior programming experience would really struggle with this. Having said that, this could easily be modified into a proper tutorial and even now its a fun thing game to try out what you learn in some other tutorial.
* "I don't really know what call means in this context, but based on previous knowledge, I'm guessing I should replace the example words with that."
* "Oh, right, I remember based on previous knowledge that "#" means comment, so I should remove that part too."
* "Oh, maybe I need the exclamation point that previously looked to me just like punctuation, because I know that code is precise about punctuation like that."
* "I don't know how to use if/else in Ruby, but I can guess that I just type 'if' and 'else', because Ruby has a reputation for simplicity."
* "I can also guess based on previous knowledge that indentation probably means something in Ruby, so I'll try indenting things."
And that's about as much guessing as I feel like doing for a game, and I'm still on level two. (I know I could easily learn how to play the game by looking at any basic guide to Ruby; I'm just demonstrating how it feels for a person without any experience.)