Taking hostages, which are basically currency in negotiations. Also, the whole attack will likely upend the Israel-Saudi normalization process that undercut Palestinian leverage, it has made many Israelis doubt Netanyahu's ability to keep them safe, will probably reduce the number of new immigrants to Israel and cause some to leave, and the fallout from Israel's response will radicalize even more Palestinians leading them to support and join Hamas. It's a risky gambit, but doing nothing was also very risky for Hamas since Israel has been aggressively consolidating its power over the last few years and moving toward annexation and the elimination of any viable path toward Palestinian self-determination