Tip for Encore/Wynn hotel guests:
You can go to the Encore concierge desk during the day and purchase prepaid tickets to XS Nightclub. Although prepaid tickets can only be purchased by hotel guests, you can purchase up to 4 tickets which means that if you have friends who aren't staying at the Encore/Wynn with you, you can still buy it for them since you can buy up to 4 tickets). There's a special line for hotel guests with prepaid tickets at the entrance of XS. We hardly had to wait on a Fri night at 11pm and basically bypassed everyone in the regular line.
Now about the nightclub itself. XS is beautifully designed and thought out with two main areas: indoor club and outdoor area. The outdoor area is basically where the Encore pool area is during the day and at night it's turned into the outdoor section of the nightclub, which makes it really nice to able to enjoy your drinks and the music right next to the pool. You can reserve a cabana if you want. They also have a few gambling tables in the outdoor area if you wish to try your luck while clubbing. The main dance floor is indoors which opens up to the outdoor area.
On Sunday nights, they have the Sunday Night Pool Party which means you can go clubbing with your swimwear.
Most expensive nightclub ever built. Loved the concept and music. Beautiful people all around. Definitely worth checking it out.