The Binding of Isaac is a game about a 5 year old stuck in hell, and in this page we will go over the places you'll go and what you probably will encounter, starting by
ROOM TYPES
We'll go over these by frequency of appearance and importance
1 - NORMAL ROOMS
The non-special room, these are the rooms that compose most of every floor in the basement.
These are rooms where you'll encounter enemies, some pickups and used to find more interesting rooms.
They can also be large rooms that are the size of 2 to 4 rooms
2 - BOSS ROOMS
The second "non-special" rooms as they're present on every floor and are required to be beaten to progress the floors.
These rooms are where the floor's boss resides, beating the boss opens the entrance for the next floor and gives you a boss item (these are mostly simple stat upgrades).
3 - TREASURE ROOMS
The first actual special room, one of the most essential and most simple.
These rooms are the primary way of getting stronger as they will always have an item in them and those items are part of a giant pool of items that can go from game changing to "oh thats a fly".
basicly a gift almost every floor.
every floor after the first you'll need a key to open these rooms.
4 - SHOPS
Shops are just like treasure rooms in frequency of appearance and entrance requirements, but inside them, instead of a free item, you can buy pickups, consumables and items from the shop pool.
There's also a donation machine to store your money for future runs
5 - ARCADES
Arcades only appear on the second floor of each chapter and are opened with a coin.
Inside them you'll usually find beggars, slot machines, blood banks, and if you have them unlocked, crane games.
Arcades usually don't hold much value but they can help you get money or some items if you're lucky, but they'll always give you atleast something.
6 - CHALLENGE ROOMS
Challenge rooms are special rooms that once you enter it'll contain a few chests and if you open any of them, the exit door will close and you'll have to fight off 3 waves of enemies for the door to open.
The entrance of the challenge rooms are closed if you don't have full health.
7 - BOSS CHALLENGE
Boss Challenge rooms work mostly like regular challenge rooms, except that instead of 3 waves of enemies its 2 waves of that floor's bosses, and instead of chests to start the waves its a boss item. You also can only enter these rooms if you only have 1 full heart (2 halves of a heart), which can make it hard but most boss items also heal you so it isn't a problem most of the time
8 - CURSE ROOMS
Curse rooms have their entrances covered by spikes, which means that you'll be forced to take damage when entering and exiting .(unless you have flight but it only works for when you enter?)
9 - SACRIFICE ROOMS
Sacrifice rooms, or sac rooms for short, are rooms that are always open and contain a single path of spikes in the middle. Those spikes can hit you even if you have flight and their purpose is to sacrifice hearts for rewards, most of the sacrifices have just a chance of happening and the rewards change for each stage or sacrifice.
10 - LIBRARIES
Libraries are rooms that will usually just contain book active items, most of the time when you find one you won't keep a book from the room unless its very good or you can take it because its not an active item. Good way to guarantee bookworm for your run.
11 - DEVIL'S ROOM
Devil rooms, or Devil deals, are rooms that have a chance to spawn after beating the floor's boss, that chance can be increased by either bombing beggars or keepers. Devil rooms contain 1 to 3devil pool items that cost heart containers to take
12 - ANGEL'S ROOM
