If you were to stumble in off the Atlantic City boardwalk — without noticing the new signage — and ride the glass escalators up to the casino floor, you’d be sure Revel had simply just reopened after four years of closed doors.

Considering the structure, the decor and the general chic grandiosity all remain mostly the same inside 60-story locale gleaming at the north end of the strip, you probably wouldn’t assume the building had just undergone a $175 million renovation, nor had it been rebranded the Ocean Resort Casino.

But then you begin to wander around and realize there is, in fact, quite a bit of change inside the 138,000-square-foot space: new entertainment, new restaurants, new attractions and, oh, a brand new sports book just in time for the legalization of sports betting in New Jersey.

The rebranded Ocean Resort officially opened Thursday, alongside the new Hard Rock (replacing Trump Taj Mahal), and while my colleagues handled the news and ceremony of the day — and Mark Wahlberg betting the Eagles to win another Super Bowl — I was behind the scenes, wandering around with no media credentials, staying the night and comparing A.C.’s (sort of) newest casino to its predecessor Revel, where I visited often in its two years of operation, between 2012 and its filing for bankruptcy and shuttering in 2014.

Here’s a breakdown of what’s new, what’s good and what you need to know before you book a room at the Ocean Resort Casino.  

While most of Ocean Resort is open to the public, certain shops and amenities are still being constructed. For instance, if you were excited to bring the kids to make-your-own breakfast nook Cerealtown listed on the website, know that it’s currently just an empty room. Same goes for the e-sports-friendly The Den. That’s not ready or meeting its online description just yet either. Other lobby areas were still being set up Thursday, with ladders and construction teams working away among the guests.

If you stayed at Revel, and dug the minimalist modern decor — blacks, whites, grays and geometrical patterns — your room at the Ocean will be a blast from a past. In other words, the rooms are the same. The 1,399 rooms have been cleaned and polished up for the big reopening, but there’s been no renovation, considering the spacious rooms were only two years old when they went dark. That being said, if your carpet had stains on it then, it has stains on it now (mine did, anyway). And a millennial pet peeve: There was no Wifi information in the room.

If you can snag a north-facing room, the floor-to-ceiling windows provide an epic view of the water and nearby Brigantine. Weeknight rates start at $149 — a relative bargain on the A.C. strip — while weekends start around $300 a pop.

The William Hill Sports Book — the first of its kind in Atlantic City — will be a major selling point for Ocean Resort as it hopes to poach gamblers away from competing casinos. The Book, located dead center on the enormous casino floor, was in full swing on Thursday, as folks wandered in, picked up some odds sheets and made their first legal sports bets in the Garden State. I was one of those patrons, dropping a whole $5 on the Cowboys to win less than eight games this year, because screw the Cowboys.

The Book had a few helpful employees on hand to explain the overwhelming pile of odds sheets — ranging from the night’s baseball game first-inning scores all the way to who will win the Super Bowl next year — to newcomers like me. It’s a big, open and inviting space with a bar and TVs to watch the freaking Jets blow a lead and, in turn, your life savings.