Prestige: what a reset takes, and what it can never touch
Reach level one hundred and a star appears in the menu. Pressing it puts you back at level one with nothing you bought and no points in hand, and gives you five per cent more from every point you earn from then on, for as long as the account exists.
It is the largest decision in the game and the one most worth understanding before pressing, so this page is mostly a list of what goes and what stays.

What it takes
Your level and your experience go back to the start. Every upgrade you bought with points goes back to zero — tap power, maximum energy, regeneration, automatic tapping, critical chance, the cooldowns and the boost duration. Passive income goes too, both the generator levels and whatever was sitting in the store uncollected.
And the points balance itself goes. That is the part people ask about, and it is deliberate: without it a player at level one hundred simply rebuys every upgrade the same afternoon, and there is no cycle at all — only a free multiplier for pressing a button.
A boss fight in progress does not survive it either. Everything else about the boss is unaffected: the four-hour clock keeps its own time.
What it can never touch
Your internal wallet, your TPC, and everything you have ever withdrawn. Your referrals and everything they have earned you. Your achievements, your badges, and the permanent lines you bought in the research lab and merged in the fusion lab.
And your withdrawal ceiling. That ceiling rises with your level, and if it read your current level a reset would cut it from forty-five tokens a week back to ten. It reads your highest level ever instead, banked in the same write that drops the level, so a prestige has never lowered it and never will. The whole ceiling is set out on the wallet page.
The rule behind the split is simple enough to state in a line: a reset takes play and leaves money. Anything you could turn into a token is on the far side of it.
Twenty of them, and where the ladder stops
The first prestige asks for level one hundred and each one after it asks for twenty more: one hundred and twenty for the second, and four hundred and eighty for the twentieth. Each pays five per cent, so twenty of them is exactly double.
It stops at twenty because a twenty-first would ask for level five hundred, which is exactly where the experience curve itself ends, and a twenty-second would ask for five hundred and twenty, which nothing could reach. A ladder whose last rung cannot be stood on is a ladder that lies.
Prestige three opens the fusion lab, prestige five opens the tree and its thirty skills, and prestige ten opens the late shop — so the ladder is also how four of the eight advanced systems arrive.