If you design your action well, you can force your target into a situation where they have no good options: where they’re “damned if they do, and damned if they don’t.” This is known as a decision dilemma.
Gandhi’s 1930 Salt March presented the British authorities with a classic decision dilemma: either beat up and arrest Gandhi and his supporters and turn them into martyrs for the movement, or let them march to the sea in open defiance of British authority and the hated Salt Act.
Many actions with concrete goals (such as a blockade or a sit-in) require a decision dilemma in order to be successful. A sit-in at a corporate HQ, for instance, should leave your target with only two options, if they are not willing to meet your demands:
1) Evict your forcibly and face the negative public attention this would cause, or
2) Wait you out, allowing you to gather more attention and support while business as usual grinds to a halt.
When done skillfully, decision dilemmas can help win major concessions from powerful targets.
In a repressive environment, or against a powerful target, you need to be sure that your action actually puts them in a decision dilemma, or you may just put yourself at serious risk.