The most important term in a startup term sheet that no one seems to think carefully about is founder vesting. There are two key points about vesting:
1) All startup employees – including founders! – should vest over 4 years from their start date (with a one year “cliff”). When I used to work in VC I can’t tell you how many companies I saw where some random former founder who was long gone from the company and was only there for some short period of time owned some big chunk of the company. Not only is this just plain unfair, it also means there is a lot less room for giving equity to employees and for raising new capital. Even if you are founding a company with your best friend – actually, especially if you are founding a company with your best friend – everyone should have vesting. If you have a lawyer who tells you otherwise, get a new lawyer.
2) Founders should always have acceleration on change of control! In particular, you should have full acceleration on “double trigger” (company is acquired and you are fired). In addition you should have partial acceleration on “single trigger” (company is acquired and you remain at company). I prefer a structure where you accelerate such that you have N months remaining (N=12 is a good number). This gives the acquirer comfort that the key people will be around for a reasonable period of time but also lets the founders get the equity they deserve without spending years and years at the acquirer. Consider the scenario where your company gets acquired 1 year after founding and you have 3 years of vesting remaining. Suppose further that you just aren’t a big company type and leave after 1 year. In that case you would forgo half your equity. It’s always surprising to me how much time founders spending focusing on valuation that might change their ownership by a few points when vesting acceleration (albeit under certain circumstances – but I have seen this happen) can have a far larger impact on their ultimate equity ownership.