How does vision score work in League of Legends

What Is Vision Score?

Vision Score is an in-game stat that indicates how much of an impact each player has had over global vision, whether for the allied team or against the enemy team. Most of how this is calculated is through the concept of ward lifetime.

How Does Vision Score Work?

Vision score follows the following equation:

VISION SCORE = (1 point per minute of ward lifetime provided) + (1 point per minute of ward lifetime denied)

The obvious main ways to influence your vision score are:

Providing ward lifetime: Each minute of ward lifetime grants up to one point of vision score, depending on how effective the ward is (more on this later). Points are given when wards are destroyed or expired. If a ward is killed by enemies too quickly after it's put down, it'll always give at least 0.33 points.
Revealing enemy champions: This includes environmental effects like Scuttle and Scryer's Bloom (former gives 0.5 points per champion revealed, latter gives one point after the scuttle expires), and champion abilities like Ashe's E, Kalista's W and Quinn's W (which give 0.33 points per champion revealed). This will generally extend to any ability that the game classifies as a source of vision.
Denying ward lifetime: Scoring takedowns on wards (getting the last hit) grants one point of vision score for every minute of lifetime remaining on the ward. Pink wards count as always being worth 1.5 minutes.

Ward Effectiveness and Negative Modifiers in Vision Wards by default grant one point of vision score per minute of lifetime, but it's often modified by infractions and modifiers. These modifiers are multiplicative, which means a ward can be affected by both staleness and redundancy, giving next to no total vision score.

Staleness: A ward that hasn't seen any enemy units will gradually go down in value, starting at 60 seconds of staleness and going down to -50% vision score at 120 seconds of staleness.
Redundancy: A ward near other allied sources of vision, such as structures, minions, champions and other wards, will have its vision score lowered by 25% per redundancy, up to 75% for 3 different redundant sources near it. If the ward is in the brush, lane minions won't apply as a redundancy.
Safety: Wards close to your base will give less vision score, starting from -0% score around your buffs, down to -50% score around base walls.
Pointlessness: Wards close to allied structures or inside your own base have a -100% modifier to their value.

Improving Your Vision Score

Here's a few tips to reliably increase your vision score if you want to make S and S+ scores more likely in your games:

Keep up ward staleness: Ward offensively in high-traffic areas, such as enemy jungle entrances, river pixel brushes and next to buffs. Most importantly, this reduces how much guessing you have to do to keep up with the enemy jungler and where they are.
Reduce redundancy: Try not to overlap sources of vision. Prioritize useful areas far away from your vision, over smaller bushes right next to your lane which you can see the other side of you just fine.
Use your wards wisely: Don’t replace wards right after they’re destroyed out of spite; it’s a waste of wards, and wards tend to be more valuable than an oracle or pink ward. Simply keep them and place them again when nobody’s counterwarding, or place them somewhere else. Your 3 wards are simply not worth controlling a tribush, when you could be controlling 2 different areas in the enemy jungle or an objective instead.
Don't underestimate warding lane bushes: Keep in mind that lane minions don't apply redundacy in these cases. If you're toplane and want to farm a little vision score, it could be a good idea to just keep a ward on one of the bushes closest to the enemy tower. It's guaranteed to be low staleness and redundancy throughout the 90 seconds, on top of being useful with laners that like fighting around the bushes (Darius, Urgot, Yorick, etc.)

And most importantly..

Actually utilize the vision! In general, maximizing non-stale ward uptime will lead you to have more information about what the enemy jungler and laners are doing, but a ward you don’t look at might as well not be there at all. Constantly try to peek at your minimap, and ping important things to your teammates. People might be too busy dueling or last-hitting to notice the jungler coming to their direction right before they commit.

Sources of Vision

Below is a list of effects that the game classifies as a "source of vision", which means, effects that grant vision over an area, or effects that reveal units directly, granting you the standard 0.33 Vision Score per enemy revealed. There are some effects in the game, like Ignite, that technically grant sight of a unit, but that require sight of the unit to begin with, so they won’t really matter for Vision Score.

Champion Abilities

Aatrox’s W
Akali’s E
Akshan’s Q and R
Aphelios’ R
Ashe’s E and R
Aurelion Sol’s E
Azir’s R
Bard’s W and R
Brand’s passive, which would indirectly make all of his abilities a source of vision if they happen to hit a champion that’s invisible or in the brush.
Briar’s R
Caitlyn’s W when the trap is activated, and R
Cho’Gath’s Q
Corki’s Q and package-empowered W.
Darius’ E and passive, which would indirectly make his Q a source of vision if they happen to hit a champion that’s invisible or in the brush. Technically, his R also grants vision of the unit while you’re casting it.
Diana’s Q
Draven’s R
Ekko’s W
Elise’s spider form E (Rappel).
Ezrael’s R
Fiddlesticks’ passive and W
Fizz’s R
Galio’s R
Garen’s R
Gangplank’s E and R
Gragas’ Q and R
Hwei’s EW (Gaze of the Abyss) and R
Illaoi’s E
Irelia’s R
Ivern’s W
Jarvan’s R
Jayce’s cannon form Q and E
Jhin’s E and R
Jinx’s R
Kai’Sa’s W
Karma’s W and empowered W
Karthus’ Q and W
Katarina’s daggers
Kayn’s R (a side note, his E technically doesn’t grant him vision, it instead just lets his vision go through walls)
Kindred’s W
Kled’s Q and E
Kog’Maw’s R
LeBlanc’s W
Lee Sin’s Q and the second cast of his E
Leona’s R
Lucian’s W
Lulu’s E
Lux’s E and R
Malzahar’s Q and R
Maokai’s R
Miss Fortune’s W
Mordekaiser’s E and R
Naafiri’s W and R
Nami’s R
Nasus’ E
Nautilus’ R
Nidalee’s passive
Olaf’s Q
Orianna’s ball
Ornn’s R
Pantheon’s R
Qiyana’s R
Quinn’s W
Rek’Sai’s tunnels
Renata Glasc’s Q and R
Rengar’s E and R
Ryze’s R
Sejuani’s R
Senna’s R
Sett’s R
Sion’s E, both the first unit hit and units hit by a creep launched by his E
Skarner’s E and R
Smolder’s R
Sona’s Q
Soraka’s Q
Sylas’s R
Syndra’s W
Tahm Kench’s W
Taliyah’s W and R
Thresh’s Q
Twisted Fate’s R
Twitch’s W
Udyr’s R
Urgot’s R
Veigar’s W
Vel’Koz’s W and E
Vex’s E
Vi’s R
Viktor’s E and R
Volibear’s W and R
Warwick’s R
Xerath’s W and R
Yasuo’s W, R, and any champions targeteable by his R
Yorick’s W
Zac’s Q
Zeri’s W
Ziggs’ W, E and R
Zilean’s Q
Zyra’s R and her seeds