One thing that I think makes ALTTPR super cool is just how many disparate item combinations lead to the same location, meaning sometimes the items you would "normally" use to access that location are actually hidden in that location.
For example, you can access the Desert Palace dungeon (the second dungeon in the regular game) normally by using the Book of Mudora to read the tablet (which causes you to pray for entrance and the statues move). But you can also enter the dungeon by using the flute to fly to location 6, using the Titan's Mitts to lift the rock covering the Dark World portal, and then mirroring directly onto the previously inaccessible ledge.
Understanding those alternate routes really opens up the decision tree.
@djmoo: The code is open source, but here's a rundown of my understanding of the algorithm. I'm going to skip and fuzz some little stuff that is important if you really want to get good at the randomizer, but not important if you just want to know the basics:
Each item location has a set of prerequisites configured in, i.e. in order to reach the boss of Eastern Palace, you need the Lamp (to navigate through the dark rooms) and a Bow (to defeat the Red Eyegores guarding the bosses room). Additionally, locations are configured to avoid "soft locks" - ways in which you can accidentally use your small keys in dungeons inefficiently that might cause the dungeon to become incompleteable. For example, the first chest in Swamp Palace must be a small key, because if it is not, you cannot access the rest of the dungeon.
First, the algorithm determines which dungeons are crystal and pendant dungeons. I'm not sure if Dan ever noticed, but in his seed Eastern Palace wasn't the green pendant, it was a crystal. It also determines which medallions are required to enter Misery Mire and Turtle Rock.
Then, all the locations in the game get randomly shuffled together into a list, and all the items in the game get randomly shuffled together into another list.
Then, the algorithm starts placing in the "dungeon items" - Big Key, Compass, Map, and whatever number of small keys that were in chests for a dungeon. The algorithm assumes that you have all the necessary items to reach every location in the dungeon when placing dungeon items.
Then, the game starts placing the required items in order to beat the game. You can set what your "goal" is for a seed - All Dungeons, pull the Master Sword, etc. - but most of the time the goal is just "Defeat Ganon." The best way to think of it is by example. Let's say the first item in the items list is the Flippers. The algorithm plucks the Flippers from the item list and starts searching for locations that are available. Since this is the first item placed, the available locations cannot be locked by any other non-dungeon item, so it places it in an easy to reach location, like somewhere in Kakariko Village. Now the next item is picked, say the Hammer. This time when its searching for a location to place the Hammer, it knows all the locations that were previously available are still available, but also the locations locked only by the Flippers are now available - like the Hobo under the bridge. Repeat until finished with the required items to finish the game.
Then, it does this same process for what are called "nice" item: items that aren't required to beat the game, but will help you on your journey. Things like the mail upgrades and sword upgrades after the Master Sword are part of the nice items. These don't unlock new locations, so this is just filler for the empty item locations.
Finally, it places the extra items. Not required at all. This can be things like heart pieces, bomb capacity upgrades, or rupee drops.
@ildon: I get that. but even outside of a race the idea of circling Light World tons of times because your progression is locked behind some really obscure location wouldn't be fun. Just a map wouldn't help to remember things like "Oh, Kholdstare is blocked by Cane of Somaria in this seed," but it would help to remember "Oh, yeah, Lumberjack ledge exists."
Dan, I'm currently participating in the ALTTP Randomizer tournament (5-0 baby). It's super cool that you're attempting it without a tracker, but you should at least have a map with all the potential locations. It doesn't have to be fancy, but just something so you don't get trolled like you did with the man in the Mini-Moldorm cave. You were still super early in the game for a Randomizer seed, and if like Lamp is at Mimic Cave and you forget Mimic Cave exists, you'll wander the world like 4 times before turning it off in disgust.
Hope you complete the seed. It's a total blast to play.
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