T-Rex: Determinism is the idea that every event and thought ever is predetermined! This determination is NOT done by fate or God or whatever, but rather by an almost endless chain of prior events. Causality is king!
T-Rex: Also: there's also no such thing as a random event!
T-Rex: A nice benefit of this is that free will is reduced to a complete illusion, since everything anyone ever does is already decided. On the plus side, this means that you can decide to do anything you want, because you're not responsible for it! But on the minus side, it means that you can't ever ACTUALLY decide to do anything. Thanks, determinism!
Utahraptor: But come on, even if free will is an illusion, it's a convincing one!
T-Rex: True!
Utahraptor: So who cares if everything is predetermined then? If it's utterly convincing that I have free will, what does it matter if it's all predetermined? I'm still affecting events in ways I choose.
T-Rex: But you'd just be lying to yourself! You're affecting events, but not CHOOSING anything.
Off panel: So how can I be faulted for that, T-Rex... IF IT WAS ALREADY DETERMINED THAT I'D LIE TO MYSELF?
T-Rex: Hooray! You pass determinism.
T-Rex and off panel: Now, let's never talk about it again!