Introduction: worms and water pumps: how can you do the most good? -- You are the 1 percent: just how much can you achieve? -- Hard trade-offs: question #1: how many people benefit, and by how much? -- How you can save hundreds of lives: question #2: is this the most effective thing you can do? -- Why you shouldn't donate to disaster relief: question #3: is this area neglected? -- The best person who ever lived is an unknown Ukrainian man: question #4: what would have happed otherwise? -- Why voting is like donating thousands of dollars to charity: question #5: what are the chances of success, and how good would success be? -- Overhead costs, CEO pay, and other confusions: which charities make the most difference? -- The moral case for sweatshop goods: how can consumers make the most difference? -- Don't "follow your passion": which careers make the most difference? -- Poverty versus climate change versus ... : which causes are most important? -- Conclusion: becoming an effective altruist: what should you do right now? -- Appendix: thinking like an effective altruist: the five key questions of effective altruism.