If you are visiting the city and having a smart phone with you. Try to download this apps Paris Metro and make sure you download the map. It does cover the city metro system and you can actually use it as a guided map to get yourself into any tourist spot in the city using the metro guide. And it does tell you how long the duration of the ride and how long you get to walk. Moving around with this apps really helps. Oh one more thing... It does tell you how much u need to pay as well :) but if you are on day pass or multiple day pass, you can ignore the fare recommendation. Day pass does help you to explore n get to everywhere in Paris. It took you from zone 1 to zone 5 and by just using your day pass ticket.
A caution is that your ticket is very small tiny paper, it's easily lost if you are not careful.
The subway system in Paris does have the restrain bar but it's not fool prove system as there r still teenager that just hop over without providing the ticket and there r no authority to stop them nor really take any action. Maybe it's just their culture if freedom. :)
If you are hopping on and off on subway one can easily see each subway station had different design on their wall. It does represent some tourist spot above the station. With that you can easily identify and hop off that station.
Paris subway is a bit dirty as compared to Munich subway. But as a whole they are still barable.