One of the best ways to raise capital (and even some awareness) for a board game is a crowdfunding site like Kickstarter or Indiegogo. There have been some very successful board game campaigns on one or both platforms. Both sites have some similarities, but they also have some major differences to consider:
Philosophy: Kickstart curates all campaigns. You have to be located in an eligible country (US, Canada, or UK) and must be approved by their staff. Additionally, you must also be 18 years or older. Therefore, the campaigns there must meet certain standards; not just any idea will make it on their platform. Indiegogo, on the other hand, has a more open borders philosophy. They encourage you to have an idea at breakfast and have it up on their site by evening. Indiegogo is also open to most people internationally. They are proponents of letting the backers decided the idea's value, not a committee.
Goal: On Kickstarter, you must reach your funding goal or you get nothing. Therefore, you have to consider very carefully what funding goal you will set. If you set the goal too high you will not achieve it. If you set it too low you still are obligated to deliver on your promises. In general, it is recommended to set a goal slightly lower then you hope to achieve. Then use flex options to encourage people to bring it up. On Indiegogo, you get to keep any money pledged (flexible) or give the money back (fixed).
Fees: Consider also the fee structure. Kickstarter takes 5% off the top. Additionally, you will get hit with around 3%-5% in processing fees. Indiegogo only takes 4% off the top. However, if you don't meet your goal they increase that up to 9%. In other words, they get an additional 5% if you don't meet your goal.