Endowed progress effect
Also said as Head start effect, Artificial advancement
People work harder towards a goal, and finish it more often, if they are given a head start, even when the amount left to do is the same. Joseph Nunes and Xavier Drèze named it in 2006.
It costs nothing and it works on anything with a bar. In their car wash study, 34% of ten-stamp cards with two free stamps were redeemed against 19% of plain eight-stamp cards, over nine months, from 300 cards handed out. Both needed eight paid washes. The result is cited a lot and a reason for the head start seems to help. The headline figure is a single field study, so measure it in your own game.
Say it
“Start the first quest at 2 of 10 with a line saying "You already found two in the tutorial". It should be true, and the player still has eight left to find.”
Where you’ve seen it
Profile-completion bars on sites such as LinkedIn start partly full, counting things you have already done as progress.
Not to be confused with goal gradient
Endowed progress is about where you start. Goal gradient is about speeding up as you near the end. A head start works partly by putting you further along that gradient.