MSI is the Mid-Season Invitational, the second biggest League of Legends tournament after Worlds. It runs each spring or early summer, brings together the regional spring champions for an international title, and uses a double-elimination bracket. China's Royal Never Give Up holds the most MSI titles with three, and you can track the MSI winner as live probabilities on Polymarket once markets open each spring.
If you searched msi lol hoping for a clean answer, you probably ran into a mess instead. Half the results explain the computer hardware brand, the other half assume you already follow League of Legends esports and skip the basics. Nobody just tells you what the League of Legends Mid-Season Invitational is, when it happens, and why it matters.
That gap is annoying when you are trying to follow the season, and it costs you money if you want to bet on it. MSI sits at the exact midpoint of the competitive year. It is the first time the best regional teams clash internationally, and the result reshapes how everyone reads the rest of the season heading into Worlds. Get MSI wrong in your head and you will misprice every team that plays it.
So here is what we are going to do. We will explain what MSI is and when it runs, how it differs from Worlds, how the format and bracket work, who has actually won it, and why it matters competitively. Then we will show you how to back your pick on Polymarket without falling for the usual traps.
We cover League of Legends esports and prediction markets for a living at RiftOdds, and every fact below is checked against public records (Wikipedia's Mid-Season Invitational entry and Leaguepedia) rather than repeated from memory. Where something is approximate or has changed over the years, we say so. We do not invent winners, dates, or results, and we will never tell you who is going to win.
What is MSI in League of Legends?
MSI stands for Mid-Season Invitational. It is an annual international League of Legends tournament run by Riot Games, first held in 2015, and it is the second most important event on the calendar after the World Championship. The name says it all: it lands in the middle of the year, after the spring portion of the regional seasons has wrapped, which is why people search for what is msi league of legends right around the time their region's spring playoffs end.
The core idea is simple. Each major region runs its own domestic league through the first half of the year. The teams that win their spring split (and, more recently, a runner-up or two from the biggest regions) earn a ticket to MSI, where they finally play against the champions of every other region. It is the first proper international checkpoint of the season, and the only one before Worlds in the autumn.
Because it gathers regional champions rather than a huge open field, MSI is smaller and sharper than Worlds. There is no group-stage grind with a dozen also-rans. Every team in the building is the best, or near the best, that its region had to offer this spring. That is what makes it such a clean read on the global pecking order halfway through the year.
When does MSI run?
MSI is a spring or early-summer event. Historically it has played out across May, with most editions from 2015 through 2024 running and finishing inside that month. The 2024 final, for example, was played on 19 May. So the rough rule of thumb is: spring splits finish in April, and MSI follows in May.
That said, the calendar is not fixed in stone. As Riot reshaped the competitive season, the timing drifted a little. The 2025 edition in Vancouver ran later than usual, with the final landing in July. So while "May" is the safe historical answer for the lol msi schedule, always check the official lolesports calendar for the exact dates of the current year rather than assuming. We keep a live calendar on our match schedule page so you do not have to dig.
The host city rotates every year. MSI has been held in the United States, China, Brazil, Germany and France, Vietnam and Taiwan, Iceland, South Korea, the United Kingdom, and Canada. The 2026 edition is set for Daejeon, South Korea, the first time the country has hosted MSI since Busan in 2022. The 2027 edition is slated for Europe.
MSI versus Worlds: the difference
This is the question everyone asks, and the answer is the easiest way to understand both events. MSI and Worlds are both international Riot tournaments, but they sit at opposite ends of the season and serve different purposes.
| Feature | MSI (Mid-Season Invitational) | Worlds (World Championship) |
|---|---|---|
| When | Mid-year, typically May (spring/early summer) | Year-end, roughly autumn into early November |
| Who qualifies | Spring split champions (plus a runner-up or two from the biggest regions) | Full season qualifiers, multiple teams per major region |
| Field size | Smaller, around 10 to 13 teams depending on the year | Larger field with a play-in and main stage |
| Prestige | Second most important international event | The most prestigious title in the game, the Summoner's Cup |
| Stakes | Mid-season bragging rights and, in some years, Worlds seeding for the region | World champion, the title the whole year builds toward |
The short version: MSI is the mid-season checkpoint, Worlds is the finale. MSI takes regional champions only and crowns the best team in the world at that moment. Worlds takes a much wider field at the end of the year and crowns the world champion. Winning MSI is a real trophy and a strong signal, but Worlds is the one that defines a legacy. If you want the full breakdown of the bigger event, we wrote a companion guide on the LoL Worlds prize pool and betting, and our Worlds hub tracks it live.
The MSI format and bracket
The msi format has evolved over the years, so be careful with old explainers that describe a setup Riot has since dropped. Here is how it has settled in the modern era.
The current event is built around a double-elimination structure. In recent editions there has typically been a Play-In Stage followed by a Bracket Stage. The Play-In Stage gathers the lower-seeded teams in a knockout format, and a small number of them survive to join the rest in the main Bracket Stage. For the 2026 edition, Riot has said the Play-In Stage will qualify just one team into the Bracket Stage, a slight tightening from previous years.
The Bracket Stage is where it is decided. Because it is double elimination, a team that loses once is not out. They drop to the lower bracket and can fight their way back. That format rewards consistency and resilience, and it produces some of the most dramatic series in the game. The 2025 edition set a record with nine best-of-five series going to a deciding game five, the most game fives in any international LoL event to date.
A few format details worth knowing if you are reading an msi bracket for the first time:
- Best-of-fives in the bracket. The deep stages are played as best-of-five series, so a single off-game does not end a team's run.
- Upper and lower bracket. Winning through the upper bracket is the cleaner path. The lower bracket is a survival gauntlet where one more loss ends the tournament.
- Format changes year to year. The number of teams, the exact play-in rules, and draft rules (the 2025 edition introduced Fearless Draft, where teams cannot reuse champions across a series) shift between editions, so confirm the current ruleset.
Back your MSI pick on a live market.
Open PolymarketA short history of MSI and its winners
MSI has been running since 2015, and its winners read like a tour through League of Legends history. The very first edition, in Tallahassee, Florida, was won by China's Edward Gaming, who beat SK Telecom T1 in a 3 to 2 final. SK Telecom T1 (now T1) came back to win the next two editions, in 2016 and 2017, becoming the first team to win back-to-back MSI titles.
Europe's G2 Esports took the 2019 trophy, the first European team to win MSI. The 2020 edition was cancelled because of the COVID-19 pandemic and replaced with an online streamathon, so there is no 2020 champion. Royal Never Give Up then went on a tear, winning in 2018, 2021, and 2022 to become the first and only team with three MSI titles. More recently, JD Gaming won in 2023, and Gen.G won back-to-back in 2024 and 2025.
| Year | Host city | Champion | Runner-up | Score |
|---|---|---|---|---|
| 2015 | Tallahassee | Edward Gaming (LPL) | SK Telecom T1 | 3 to 2 |
| 2016 | Shanghai | SK Telecom T1 (LCK) | Counter Logic Gaming | 3 to 0 |
| 2017 | Rio de Janeiro | SK Telecom T1 (LCK) | G2 Esports | 3 to 1 |
| 2018 | Paris | Royal Never Give Up (LPL) | Kingzone DragonX | 3 to 1 |
| 2019 | Taipei | G2 Esports (LEC) | Team Liquid | 3 to 0 |
| 2020 | Cancelled due to the COVID-19 pandemic | |||
| 2021 | Reykjavik | Royal Never Give Up (LPL) | DWG KIA | 3 to 2 |
| 2022 | Busan | Royal Never Give Up (LPL) | T1 | 3 to 2 |
| 2023 | London | JD Gaming (LPL) | Bilibili Gaming | 3 to 1 |
| 2024 | Chengdu | Gen.G (LCK) | Bilibili Gaming | 3 to 1 |
| 2025 | Vancouver | Gen.G (LCK) | T1 | 3 to 2 |
By region, China's LPL leads with five MSI titles, South Korea's LCK has four, and Europe's LEC has one. North America has reached two finals but has never won. If you want the single fact to remember, it is this: Royal Never Give Up is the most successful MSI team in history with three titles, and Gen.G and T1 are the only other multi-title organizations.
Why MSI matters competitively
MSI is more than a trophy. It is the first hard data point the entire scene gets on how the regions stack up against each other this year. Domestic leagues are sealed bubbles. A team can look dominant at home and then get exposed the moment it faces a champion from another region. MSI is where that gets tested.
That has real downstream effects. A strong MSI run tells you a region's meta and talent are ahead of the curve, and in some years MSI results have fed into Worlds seeding for the region. It also resets expectations. The team that wins MSI instantly becomes a Worlds favorite in most people's eyes, and the regions that flop spend the summer scrambling to adjust. For anyone who follows the season closely, or bets on it, MSI is the single most informative event before autumn.
For bettors specifically, that information is gold. The prices you see on later markets, including Worlds, are shaped by what happened at MSI. Understanding that link is half the reason we tell people to watch the event even if their favorite team is not in it.
How to bet on MSI via Polymarket
Polymarket is a prediction market, which means you are not betting against a bookmaker with a baked-in margin. You are buying and selling shares in an outcome against other people, and the price of a share moves with the crowd's collective estimate of the odds. A share that costs 25 cents is the market saying that outcome has roughly a 25 percent chance. If it happens, the share settles at one dollar. If it does not, it settles at zero.
For an event like MSI, Polymarket typically lists a "winner" market where each team gets its own line and a price that adds up, across all teams, to roughly 100 percent. These markets open each spring as the field firms up, so you will not always find an MSI market sitting live in the off-season. Here is the sane way to use one:
- Read the price as a probability. A team at 40 cents is the market's way of saying about a 40 percent chance, not a lock. Treat it as the crowd's estimate, not a promise.
- Look for disagreement, not certainty. The edge is when you genuinely think a price is wrong based on form, draft, or roster news, not when you simply like a team.
- Remember you can sell. Because it is a market, you can exit a position before the event resolves if the price moves your way. You are not locked in until the final.
- Size it sensibly. Stake an amount you are fully prepared to lose, and never chase a loss with a bigger bet.
If prediction markets are new to you, start with our walkthrough on how to bet on League of Legends, which covers wallets, funding, and the mechanics step by step before you put real money near an MSI line.
Betting on esports is for adults only (18+, or the legal age where you live). Odds are probabilities, not guarantees, and even a heavy favorite can lose a best-of-five. Only stake money you can afford to lose, set a limit before you start, and step away if it stops being fun. If betting ever feels like a problem, reach out to a support service in your country.
Frequently asked questions
What does MSI stand for in League of Legends?
MSI stands for Mid-Season Invitational. It is an annual international League of Legends tournament run by Riot Games, held in the middle of the year, and it is the second most important event after the World Championship.
What is the difference between MSI and Worlds?
MSI is the mid-season event, held around May with the regional spring champions and a smaller field. Worlds is the year-end World Championship, held in autumn with a larger field and the most prestigious title in the game. MSI is a checkpoint; Worlds is the finale.
When is MSI 2026?
MSI 2026 is scheduled to be held in Daejeon, South Korea, the first time the country has hosted MSI since 2022. MSI has historically run in May, but exact dates shift year to year, so check the official lolesports calendar for the confirmed schedule.
How many teams play at MSI?
It varies by edition. Recent MSI tournaments have featured roughly 10 to 13 teams, drawn from the spring champions of each region plus, in the biggest regions, a runner-up or two. The exact field size is set by Riot each year.
Who has won the most MSI titles?
Royal Never Give Up from China's LPL is the most successful team in MSI history with three titles, won in 2018, 2021, and 2022. T1 (formerly SK Telecom T1) and Gen.G have each won two.
Can you bet on MSI?
Yes. On Polymarket you can buy and sell shares in the MSI winner, with each team's price reflecting its implied probability. These markets open each spring as the field is confirmed. Remember it is for adults only and that prices are probabilities, not guarantees.