How many people are really playing Sea of Thieves?

There’s been “10 million players”. But does that mean anything?

In January Joe Neate announced (via Xbox Wire) that Sea of Thieves had passed 10 million players since launch.

We’re excited and humbled to share that Sea of Thieves has now been played by more than ten million players, reinforcing its status as the most successful new IP from Xbox this generation.

The news was met with some scattered derision around Reddit and other venues. Commentary has ranged from skepticism that the number is even real, to anger that Rare is trying to make it sound like the game is more popular than it is.

Many said that reporting 10 million players isn’t any indication of anything.

So let’s take a look at all of the publicly announced figures (of which there are some, but not a lot) to get a handle on what it all really means. (tl;dr).

Total players

Rare and Xbox have periodically announced player numbers throughout the life of Sea of Thieves. Here’s what we know:

What do these numbers represent?

It’s safe to assume these are unique Microsoft Accounts who have at least opened the game on PC, Xbox or via Game Pass.

We don’t know exactly what the baseline threshold for inclusion is. Launching a game into the splash screen is enough for the action to be counted for Game Pass Quest rewards, so it’s possible that’s what counts as a player for these announcements. Or, it might be that a player at least has to create a player and load into a game server.

It almost certainly includes alt-accounts, where a single real person has multiple Microsoft accounts, and uses them to log in to the game with separate pirates for various reasons. I’m not convinced alts exist in any meaningful numbers for the point of this discussion. 10,000 total alts would equate to just 0.1% of the 10M number, and even 100,000(!) alts would equate to just 1%.

And yes – to all the Captains of the Obvious Brigade – 10 million is a unique player count. It includes all the people who have played for 30 seconds and never touched the game again, as well as all the people who have played thousands of hours.

New players per month

Although the total players announcements are fairly limited in their scope, we can wring out some interesting information by considering when they were announced.

Sea of Thieves got off to a cracking start, numbers wise. It was the first of the first-party Xbox Studios games to launch day-and-date into Game Pass. This resulted in 1 million players in the first 48 hours (despite some pretty hectic server issues), with 2 million players reached after a week.

Growth stayed strong over the next few months, with the 5 million player milestone announced at the end of July. This averages out to roughly 750,000 new players every month from April to July 2018.

The next player count announcement was made at E3 2019, confirming a total of 8.4 million players. This meant the game attracted 3.4 million new players over the previous ~11 months, averaging out to around 310,000 new players every month from August 2018 to June 2019. It’s worth keeping in mind that the Anniversary Update released during this period, although it’s possible that event drove a lot of returning players while giving a slight bump to the amount of new players too.

Which brings us to 10 million. That number is a 1.6M increase on the previous announcement from 6 months prior, averaging out to around 260,000 new players per month for last 6 months of 2019.

The slowing growth here is pretty normal for an established game, but 260,000 new players per month is nothing to sneeze at, considering it equates to roughly 1 million new players every 4-5 months.

How many “active” players are there?

Oh, the downvotes I’ve received when trying to figure out exactly what people mean when they use the phrase “player base”. It certainly has a colloquial meaning, but when you’re dealing with actual numbers it’s useless unless you define the terms of what you’re discussing.

It just means the amount of people that are playing a game.

Oh, /u/danny686, you’re killing me here.

When measuring active users, one of the most common metrics is Monthly Active Users (or MAUs). This captures the number of players (or, in our case, what we assume to be unique Microsoft Accounts) who sign in to the game at least once per calendar month.

Rare surely measure a huge range of telemetry including Daily Actives, concurrent players, rolling 60 or 90 day actives, and many more. Sadly, we’ll almost certainly never get access to some of these ‘grittier’ numbers.

On the rare occasion however, the Sea of Thieves team have announced how many unique players have been active within certain date ranges…

E3 2019

The first of these was part of the afore mentioned Inside Xbox stream. During his chat with Major Nelson, Joe noted exactly how many players had experience the Anniversary Update.

Since Anniversary launched we’ve had over 2 million people [who’ve] played, just since Anniversary alone. And it’s our third highest month, in terms of monthly active users, since launch.

A few careful notes on this. Firstly, a safe assumption is that “people” in the 2 million number are unique players, especially since Joe immediately follows up with a MAU reference.

Secondly, the Anniversary Update went live on April 30th 2019, and Inside Xbox aired June 10 – which means the “over 2 million” number is taken from a 40 day period (give or take a day). From this we can estimate that the MAUs for May was likely over 1.5 million.

Thirdly! The fact that May 2019 had the third biggest MAUs since launch helps us validate against what we already know about the launch numbers: 2 million in the first week, 4 million by ~6 weeks.


Then, in December 2019, the Sea of Thieves social accounts shared some stats from the launch of the Seabound Soul (November 20th) through December 3rd.

One of the more interesting stats is “608,991 players on fire”. I followed up with Joe Neate to confirm if that meant total instances of people catching fire, or unique players who’d caught fire at least once. To my surprise he replied:

609,000 unique players over a 2 week period is not insignificant.

It does bear keeping in mind that the Seabound Soul update contained the first new Tall Tale since the Anniversary Update, and featured fire for the first time too, so there is potentially a bump here compared to a ‘smaller’ release.

For the love of the Pirate Lord, TL;DR?

Yes, sorry, I’ve gotten a bit carried away here. Let’s sum up.

Yes, there really have been 10M Microsoft Accounts that have, at the very least, launched the game. Alt-accounts barely effect this number (10 million is a lot, you guys). No, it doesn’t mean Sea of Thieves has 10M active players. It’s a nice milestone to talk about and use in Marketing comms.

Through the second half of 2019, around 260,000 new players fired up Sea of Thieves for the first time every month. This growth will continue to slow, although it remains to be seen what other events may impact this (Game Pass promotions, price drops, next gen consoles, future updates, etc).

Using 2M players over 40 days, and 609K players over 13 days as examples, we can estimate that monthly active uniques are likely in the range of 400,000-1M players, depending on the time of year and scope of that month’s release. MAUs exceeding 1M from time to time certainly wouldn’t be surprising. 90-day active uniques may even approach 2M or more, but I’m really spitballing on that one.

In November 2019, Rare studio head Craig Duncan stated that “Sea of Thieves that still has millions of people playing it”, which lead to reactions like:

Well. Now you know.


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