How to list entries related to a category + related to a section?
When you call this:



craft.entries({section: 'games'}).relatedTo(category).relatedTo(craft.entries.section('reviews'))


that second relatedTo param is just overriding the first one. Lucky for you, that parameter does accept multiple criteria (see the “Passing Multiple Relation Criteria” section on http://buildwithcraft.com/docs/relations#the-relatedTo-param).

{% set games = craft.entries({
    section: 'games',
    relatedTo: ['and',
        category,
        craft.entries.section('reviews').status(null)
    ]
}) %}


It's a good idea to specify that category will be a target element (where the Games entries did the selecting), and that the Reviews will be source elements (where the Games were selected by the Reviews), as this will slim the DB query down a bit:

{% set games = craft.entries({
    section: 'games',
    relatedTo: ['and',
        { targetElement: category },
        { sourceElement: craft.entries.section('reviews').status(null) }
    ]
}) %}