What is a min-cash in poker?

A min-cash is finishing in the lowest paid position of a tournament - the smallest prize that still counts as making the money, as opposed to busting on the bubble and winning nothing at all.

Min-cash equity is real and guaranteed, and ICM prices it into every short stack's equity once a player has crossed into the paid positions, or is close enough that surviving to them is the dominant consideration. It's a large part of why short-stack ICM strategy is so much more conservative than chip-EV strategy would suggest near the bubble.

In most tournament structures the min-cash is small - commonly around 1.5 to 2 times the buy-in - which is why it is a poor target to play toward and a real number to price in. Those are different things. Folding a marginal spot on the bubble because busting costs you a guaranteed min-cash is correct arithmetic. Folding good spots for two levels *after* the bubble to protect the same min-cash is not, because almost all of a tournament's expected value sits in the top few places, and a stack nursed to 40th of 40 paid has converted a real shot at the final table into roughly nothing.

The asymmetry is worth stating plainly: a min-cash is usually a losing session. Clearing the bubble with three big blinds recovers a fraction of the buy-in, while the equity given up to get there - folded shoves, folded calls, blinds surrendered - is often worth more than the prize being protected.

The one situation where playing directly for the min-cash is correct is a satellite, because there the min-cash and the top prize are the same thing. Every seat pays identically, so surviving is the entire objective and accumulating chips beyond a safe seat buys nothing at all.