Ranked Arenas - (All information we need)

EA has published all we need to know about Ranked arenas:

Source: https://www.ea.com/games/apex-legends/news/arenas-ranked 

Maps

• King’s Canyon - Hillside
• World’s Edge - Dome
• Olympus - Oasis

Penalties: Will be the same as Current BR Ranked

Gain/lose Points: RP is called AP (Arena Points). You can only gain them by winning, kills won't give extra AP. Also, there is no entry cost on any rank.

Ranks: Will be the same as Current BR Ranked, from Bronze to Predator

Ranked MMR Explained:

Quoted from the page:
"If you’re new to a system like this, it might not be obvious why we wouldn’t always keep these numbers the same. You might ask: Shouldn’t a Silver player always have the same MMR as other Silver players? 

In theory, yes, which is why for the most part your rank and your MMR will stay closely tied. But keeping the two scores separate comes with some major benefits, the biggest being that we can quickly adjust your MMR up or down based on your performance, without making you lose your rank just because of a few bad matches. Those quick adjustments means that matchmaking quality (the odds of you being paired against someone of similar skill) goes up."

"So, as an example: If you find yourself ranked Silver, but you’ve been consistently playing at a Platinum level, our system will go ahead and start matching you against other players with Platinum-level MMRs. If you win these matches, you’ll get a lot more Arenas Points (AP), which will make your visible rank catch up to Platinum quicker. If you lose these matches, likewise, you’ll lose fewer AP, and your MMR will invisibly drop until you’re matched more evenly."

"When you first play Ranked Arenas, you start in placement matches. Your performance over these 10 matches will determine your initial MMR and your starting rank. MMR variance is wider initially, so these first 10 matches might be stomp-or-get-stomped until your MMR settles more."