If you‘re just a regular employee with some options, and the acquirer doesn‘t want to keep you on, you should expect nothing.
So they're getting the employees' shares without compensating the employees?
And there's incentives paid to the people who approved the deal, separate from their shares?
(I've heard of liquidation preferences, but never by the person making a job offer with stock options. Bribery also never came up.)
Shareholders are of course free to sue the board for acting outside of the interests of the shareholders overall, but this happens very rarely because typically the company would otherwise be shutting down and it’s very hard to make the argument that the deal undervalues common shareholders’ shares.
(The two most recent offer equity components I accepted were "2%" and "a million shares". On the latter, an upper exec did a kind of deal-closer meeting for their offer, showing me a spreadsheet, estimating how much the options would be worth if there were an exit in X years at $Y valuation.)
Early employees' options will have value, but more recent options are likely underwater.
I've never bothered to understand the details since none of the private companies I've worked for have had the non-cash portion of their comp be worth anything but $0 before.
Bitter about VCs? Me? Never.