what the label actually means
Everything here can be obtained before the Wall of Flesh dies for the first time in a world. Nothing on the list becomes unobtainable afterward, so this is not a checklist you have to clear before moving on. It is a map of what a world can give you while it is still in its first state, which matters for two reasons: it tells you where the ceiling is when you are planning a run, and it tells you what to stockpile in a spare world when a hardmode one has already burned through its easy resources.
tools are the real progression track
Weapons are interchangeable early. Pickaxes are not. Every material gate in the first half of the game is a pickaxe gate, and the chain runs copper or tin, then iron or lead, then silver or tungsten, then gold or platinum, then the evil-biome pickaxe made from demonite or crimtane, then the Molten Pickaxe that finally takes obsidian and hellstone. That last one is also the only pre-hardmode tool that can touch the first hardmode ore, so it is the item you must have before killing the Wall.
The Reaver Shark is the shortcut. It is fished out of the ocean rather than mined for, and it jumps several rungs of that ladder without you smelting a single bar, though it stops short of hellstone. If you fish at all, cast in the ocean early.
hammers and axes are not the same job
A hammer is the only thing that removes background walls, and it is also how you make slopes and half blocks, so building and dungeon looting both stall without one. An axe only fells trees, cacti and giant glowing mushrooms. Placed wood and platforms come back up with a pickaxe, which surprises people the first time they try to axe a house apart. Hamaxes cover both roles in one inventory slot, which is worth more than the raw speed of a dedicated pair when you are travelling light.
movement accessories carry the whole era
The largest block of this list is movement gear, and it is where your power actually comes from before hardmode. The boots line runs Hermes Boots into Spectre Boots with Rocket Boots, then into Lightning Boots, then Frostspark Boots, then Terraspark Boots once you have Lava Waders. The balloon and bottle line does the same for jumping. Every one of those combines is done at the Goblin Tinkerer, so freeing him is worth more than most weapon upgrades.
Fledgling Wings are the only wings available this early, and they come from a sky island chest rather than a boss. If you find a pair, the exploration difficulty of the whole first act drops.
the things that are easy to miss
- Expert-only accessories such as Worm Scarf, Shield of Cthulhu, Royal Gel, Brain of Confusion, Hive Pack, Bone Glove and Bone Helm only exist in treasure bags, so a Classic world simply cannot produce them.
- Enchanted Sword and Terragrim come from the same buried shrine, and it is a coin flip which one you get, so finding a second shrine is the only way to be sure of both.
- Shadow Key opens every shadow chest in the underworld and never breaks, which makes one dungeon run pay for a whole tier of gear.
- Fishing quest rewards, including the Zephyr Fish and most of the informational accessories, arrive one per in-game day and cannot be rushed.
what survives the transition
Most pre-hardmode weapons stop being relevant within an hour of the Wall dying, because the new enemies carry enough defense to eat a small hit almost entirely. A handful bridge the gap well enough to get you to the first ore tier: Nights Edge, Sunfury, Molten Fury, Phoenix Blaster, Flower of Fire and Imp Staff, especially reforged.
Tools and accessories are different. Nothing on the movement list gets replaced quickly, informational accessories keep working forever, and the crafting materials for the mechanical boss summons all come from this era, so iron, lead, bones and lenses are worth hoarding rather than selling.