In case you haven’t used this guide yet, this Chapter, like all the others, has an element of nonlinearity to it. All you really have to do are those marked as being required; everything else, while very helpful (and typically required for 100% completion), is optional. You also don’t usually have to do things in the order we name. Below is simply an order we recommend to the events you do, clearly following the NavMap’s list and the chronological order of events in FFX to as much of an extent as possible.

The numbers within the parentheses account for the percentage contribution of that area towards 100% completion. By the end of the Chapter 4, if you did everything right there and prior to there, you should have a 75.6% completion rate on your save file, which will be viewed as 75%. By the end of Chapter 5 (and thus, the game), you will have 100% completion so long as you do every little thing right in the game.