[flanbiscuit]

when I began work at a startup once there wasn't explicit language that said they would own what I came up with outside of the office but the language in the contract was vague enough to me that I felt it could be interpreted that way. It also asked me to disclose any existing items. I had them change the language to specifically mention that they would own anything I worked on while inside the office on their computers but I would own anything I did outside of the office not on their computers. I didn't really have anything going on personally at the time but I wanted it clarified just in case. So they key here is that you can negotiate and get them to change things to fit your needs. Like everyone else is mentioning here, take the contract to a lawyer.