Free Weekend Event for Xbox One's Elder Scrolls Online Coming Soon
You'll just need Xbox Live Gold.
While ESO has long since ditched its monthly subscription fee, it does still require you to buy the game itself in order to play. That won't be the case during a free "weekend" event that lasts the better part of a week.
It starts on Wednesday, November 23, at 12:01 AM EST (9 PM PST on November 22) and runs until Sunday, November 27, at 11:59 PM EST (8:59 PM PST). Once the event is underway, you'll be able to initiate the download from the Xbox Store. You'll need a fair amount of free space open, as the game requires about 80 GB.
In addition to free access to the game, players will receive 500 crowns to spend on anything on the Crown Store. There you'll find a variety of cosmetic options available for purchase alongside a variety of upgrades, most costing more than 500 crowns (though crowns will be on sale).
Should you want to continue playing after the free play event, your saves will transfer (and any Achievement you earn are yours to keep). The game itself will be discounted during the event, though sale prices weren't specified in the announcements on Bethesda's website or the Xbox Wire.