Here are the rules set out in the Master List:

What is a scavenger hunt?
Scavenger hunts are a popular and fun challenge undertaken by Letterboxd users where the aim for each participant is to watch and review 30 different films in the space of one month based on specific criteria. The host for each month crafts 30 different tasks that each participant must find a film for, ranging in variety and difficulty.

How do I participate?
All you have to do is create your own list that fills the criteria below and post it into the comments on this thread. Once you have done that I will add your name and your list up here, and once we get underway you simply have to watch and review each of your chosen films. Be sure to include a link back to this thread in each of your own lists so others can participate if they want to, and also make sure you number your lists so they can be cross-referenced easily. I would also recommend adding the respective tasks to the comments of each film on your list.

What other rules are there?
The majority of films you watch should have been previously unseen - personally I'd say at least 25 of the 30 - and all films (unless specified) must be feature-length (60+ mins). You can't use one film for more than one task. You should also make it clear at the top of each review that you watched the film as part of this challenge.

Anything else?
Reviews in other languages are allowed, you can watch your chosen films in any order and you are allowed to change your list at any given time providing your choice meets the criteria.

What else can I do?
These scavenger hunts are designed to be community-based challenges so please take the time to read, comment and like the lists and reviews of others. It makes the whole shebang much more enjoyable if we all take the time to interact with one another. Also be sure to tag each of your lists and reviews with the terms "scavenger hunt" and "scavenger hunt [number]" so others can find them with ease.

This month's prompts are provided by cadburyhedges