How to Watch (And Understand) Some of the World’s Fastest Videogame Players

Believe it or not, “speedrunning” is something you do while sitting down. And it’s sometimes incredible to watch.

At least in the videogame world, speedrunning refers to playing through a game as fast as possible. It’s something a subculture of gamers practice year-round, broadcasting to followers on Amazon subsidiary Twitch and organizing on a 17-year-old site called Speed Demos Archive to compare their times and learn new techniques from their peers.

Since 2010, Speed Demos Archive has hosted live events that bring these speedrunners together in one place, and today the first one of 2015 — Awesome Games Done Quick — begins. Starting this morning at noon ET, and going 24 hours a day until 1:00 a.m. on Jan. 11, “runners” will be playing through games from the Hilton at Washington Dulles airport in Herndon, Va.

In addition to letting people see games played at an extremely high level (with devotees playing the same games over and over, every second matters), the marathon always has a charitable goal. This year, Awesome Games Done Quick is fundraising for the Prevent Cancer Foundation. The 2014 edition of the event raised more than $1 million for the same charity.

Less than an hour and a half into AGDQ, more than 100,000 viewers were watching the Twitch livestream worldwide.

“What’s your average viewer count?” a commentator asked the first speedrunner, Michael “Goldfish” Mescheder, after the stream crossed into the six digits.

“Like, six,” Mescheder said. “Six on a good day.”

In that span of time, the marathon had already raised about $15,000 — a number that then quickly shot up thanks to a $10,000 donation from Minecraft creator and speedrunning fan Markus “Notch” Persson. At the time of this writing, more than $55,000 has been raised.

For non-fans and casual players, understanding a speedrun can be a bit difficult at first. As a public service, a few terms that might help you follow the livestream.

Strat is short for “strategy.” Getting through a game as fast as possible means taking advantage of a game’s quirks and bugs, and discovering new strats before other people who play the same game is often the key to breaking records.

Sequence breaks are a common strat, finding glitches that let players access normally disallowed parts of a game.

Any% is a term you’ll see in a few spots on the AGDQ schedule, and is used to indicate that a runner is only trying to finish the game, not necessarily complete every level or collect every item. As I write, a player is trying to 100% the Nintendo 64 game Banjo-Kazooie, which means (wait for it …) collecting everything in the game.

IL is short for “individual level.” Frequently with games that have multiple active speedrunners, one player might have the best overall any% or 100% time, but someone else will have the fastest time for one level or part of the game. Even though multiple players may know the same strat, pulling them off can take lightning-fast reaction times — and hours of practice.

RNG is short for “random number generation,” and is a frequent foil to even the most experienced speedrunners. Games whose enemies move randomly, for example, can upset a player’s momentum and cost him or her precious seconds in unexpected ways.

Specific to the Games Done Quick marathons (the other one, Summer Games Done Quick, takes place in July) are two long-running memes: “Save the animals” and “kill the animals.” Speedrunners of the game Super Metroid, just before finishing it, can choose to either rescue or ignore a room full of animals after defeating the final boss; saving them, while optional and time-consuming, very slightly changes the ending of the game. The marathon’s organizers let donors choose what the Super Metroid runners do — a silly in-joke, maybe, but one that brought in an estimated $75,000 last year.

This article originally appeared on Recode.net.