This is way off topic, but that kind of simple gamification is "broken" because there are three Nash equilibrium, only one of which is actually marking spam cor

This is way off topic, but that kind of simple gamification is "broken" because there are three Nash equilibrium, only one of which is actually marking spam correctly. If everyone marks everything as spam, then anyone not also doing the same is "punished" because they are missing out on points they could get by marking more things as spam. If everyone is marking everything as "not spam" then anyone marking spam as spam correctly is punished as having "false positives" because everyone else is marking it not spam. To prevent those bad outcomes (which happen very quickly in some situations, I'll try to dig out real-world examples later) you need to know what is "really" spam and what isn't, but if you know that then you've already solved the problem you set out to solve with this system.