There is a weird disease called "Pokerus." It has absolutely no effect on the Pokemon it infects (as far as I know), and it goes away on its own. But that's just the thing. In the early stages, it would occur all the time, but I've restarted multiple times throughout the years, and it no longer occurs, even in my new files. Can you tell me what the deal with this is?
FO's Verdict: According to several sources I've researched, it doubles the Pokemon's earned experience points. Yeah, weird. A virus that actually does something good with no ill effects. Wonder what they'll think of next?
To be technical, Pokérus doubles not experience points, but "effort values," which are invisible values that factor into the calculation of each of a Pokémon's stats (along with level and the individual Pokémon's random genes). Effort values increase every time you eat vitamins or defeat a Pokémon, and are independent of experience points. It's because of effort points that wild or Rare Candied Pokémon generally have weaker stats than trained Pokémon.
Each Pokémon stat (Attack, HP, etc.) can get up to 255 effort points. At level 100, every 4 effort points is worth one point
in stats. Your Pokémon gets 1 to 3 effort points for each Pokémon he beats (for instance, an enemy Gengar gives three effort points to the Special Attack of
the Pokémon that beats it). Pokérus doubles this amount, allowing a Pokémon to reach its effort caps more quickly. It's not vastly useful, but it saves a
lot of time, especially for competitive Pokémon players (yes, there exists such a thing).
