Scam, an attempt to swindle

Scheme (programming language), a minimalist, multi-paradigm dialect of Lisp

Pyramid scheme, a non-sustainable business model involving the exchange of money primarily for enrolling other people

URI scheme, the outermost part of internet URIs

Scheme (mathematics), an important concept in algebraic geometry

Housing scheme, Scottish way of saying "Housing estate"

Color scheme, a set of colors chosen to be used together in some media

Get-rich-quick scheme, a usually flawed or fraudulent scheme for earning money with low risk

Rhyme scheme, the pattern of rhyming lines in poems and lyrics

Numbering scheme, an agreed-upon method of assigning nominal numbers to entities

Collective investment scheme, many people investing money together, cf. Mutual fund