How EXP and rarity work on Spielerando

On Spielerando every achievement is worth EXP, and the rarer it is, the more it is worth. This article explains where rarity comes from, how it becomes EXP, and how your rank is calculated.

Where rarity comes from

Rarity is the share of players who have unlocked an achievement. We take it from each platform directly:

• Steam publishes global unlock percentages for every game.
• GOG shows rarity for each achievement on public profiles.
• RetroAchievements tells us how many players unlocked an achievement and how many played the game; rarity is the ratio of the two.

That means rarity is measured against everyone who plays the game on that platform, not just against Spielerando users.

From rarity to EXP

The formula is simple: EXP = 10 × (1 + log₂(100 ÷ rarity)), rounded, with rarity in percent (at most 100, at least 0.1). Each time an achievement gets half as common, it is worth 10 EXP more:

Players who have it	EXP
100%	10
50%	20
25%	30
10%	about 43
1%	about 76
0.1% or fewer	about 110

If a game is a Meta Game, this value is multiplied by its tier: ×3 for Legendary, ×2 for Epic, ×1.5 for Rare.

Your total, your ratio, your rank

• EXP on your profile is the sum of all your achievements' EXP plus the EXP from your meta achievements.
• EXP ratio is your achievement EXP divided by the number of achievements you unlocked. A high ratio means you go for the hard ones rather than collecting easy unlocks.
• Rank is your place on the global leaderboard, ordered by total EXP. You can also filter the leaderboard by platform.

When does it update?

Your linked accounts sync when you link them, when you press "Sync now" on your account page, and automatically every few hours. Rarity is refreshed about once a week per game, so EXP values can move slightly as more people play a game.