Can the rarity of gaming achievements change in time?
Yes, this is theoretically possible for some achievements. If this occurs, we are guided
by the principle that the law has no retroactive effect. In other words, karma wont be
recounted and tokens wont be accrued. The rarity of achievement depends on the
gamers activity, so RAWG does not take a risk by re-calculating karma, as it can make
the system vulnerable to exploits.