As I was playing CT the other day, I noticed that the game has a massive paradox. Here goes:
Crono learns about Lavos in 2300 AD, after Lavos ravaged the land. Later, he kills Lavos at 1999 AD, and the world is saved. Presumably, 2300 AD is not destroyed, and is prosperous. Here's the problem. Now that the future is safe, when Crono goes there in the first place, he will not learn about Lavos, and therefore will not defeat him. This, in turn, means that Lavos will destroy the Earth at 2300 AD.
I haven't played Chrono Cross, so if this is actually a stupid question, please let me know.