Crates - Official Terraria Wiki

↑ 1.0 1.1 Information taken from the Desktop 1.4.0.5 source code, function FishingCheck_RollItemDrop() in Terraria.Projectile.cs; assuming actual FP is 100, not displayed FP, which is different on Desktop, Console, and Mobile. There may be inaccuracies, as the current Desktop version is 1.4.4.9. ↑ Obsidian Crates and Hellstone Crates are technically a Plentiful catch, but occur only 1 in 5 successful crate catches. This makes the lava crates technically 5× rarer than other crates, but because there are no lava catches in the Plentiful, Common, or Uncommon quality slots, lava crates are not actually much more rare than (and, depending on the player's Fishing Power, they could be much more common than) other crates in their respective environments.