Generally, a Release of Liability is a legally binding contract in which you waive your right to sue an individual or organization for the injuries, losses, or damages you suffer as a result of their actions. However, there are instances in which you may still be able to pursue legal action despite signing a release. For instance, you may still be able to sue if you've signed a release but have suffered a human rights violation, such as racial discrimination. Although you waive your right to sue when you sign a release, a fundamental human right is a right you cannot waive. This can only be taken from you by due process of law. Usually, courts will readily enforce a good-faith waiver entered into by consenting parties. However, to decide what constitutes a good-faith waiver, courts tend to consider a number of factors:
If the parties fully understood the context of the waiver
If it appears one party was taken advantage of by the other
If consideration (money or a practical benefit) was exchanged
If the waiver is so general that it's effect would be unconscionable (i.e. excessive or beyond reason)
If the waiver seeks to waive a releasee's duty to exercise due care (e.g. if an unlicensed driver drove a tour bus into a ditch, the tour company could not use the passengers' signed activity waivers as a defense in court)
To understand how different waivers are enforced in your jurisdiction, it's recommended you consult your local laws or an attorney.