We tend to picture the future as a single track: the plan, the path, the five-year goal. But a life is really a tree of forks — each decision opens some branches and closes others, and chance plays its own hand at every node. A decision tree is just an honest drawing of that shape, with the odds and outcomes made explicit instead of left to intuition.
The anatomy of the tree
The root is you, today — your real accounts, income, and current wellbeing. A decision node is a fork you control: take the job or don't, move or stay. A chance node is a fork you don't: the promotion lands or it doesn't, the market is kind or it isn't. A segment — the stretch of time along a branch — carries its own dynamics: income, expenses, growth, one-time costs, a duration, and the wellbeing you'd feel living it.
Two numbers on every branch
What makes Mentat's tree different from a flowchart is that every path is quantified on two axes at once. Net worth is projected forward by a real financial engine over each segment's cashflows. Wellbeing — a subjective score you author against a consistent rubric — is integrated over time into "wellbeing-years." A leaf at the end of the tree isn't just "you became a lawyer"; it's a dollar figure and a lived-experience figure, side by side.
Probability makes "safe" earn its name
Each branch carries a likelihood, and siblings normalize into probabilities, so cumulative path odds flow down the tree. This is where the tree pays off: the "safe" choice often isn't, once you price the outcomes you'd rather not picture. A probability-weighted tree forces the comparison the gut skips.
Utility: collapsing the tree to a decision
In the end you have to choose. Mentat combines the two axes into a single utility score — U = x·(net worth) + (1−x)·(wellbeing-years) — where x is a slider you set between "money matters most" and "how I live matters most." Slide it, and the highest-utility path lights up. The weighting is yours; the math is just bookkeeping on your own priorities.