The Binding of Isaac may appear like a simplistic shooter at first glance but you will soon find out just how hard and complex it can be. This page will list some of the best tips you can follow to increase survivability as well as "secret" techniques you can use. This page is not just for beginners; there are plenty of things I had no idea existed even after 20+ runs!
Flying Upgrades are Best Upgrades!
When presented with an item choice, always go for the one that gives Isaac the flying ability. These items include Holy Grail, Transcendence, Lord Of The Pit, and others. You have no idea how much help a flying upgrade will be when it comes to getting hard to reach items and to avoid enemy bullets. Some rooms can be "nullified" when you have a flying upgrade because you can simply stand in an unreachable place and shoot at enemies.
Although The Ladder is not a true flying ability, it is still better than nothing since it lets you cross a single gap.
Use Bombs to Escape Rooms
In a sticky situation you can use a bomb to blast open a door and escape from the room even if monsters are still present. Any monsters you have already killed will respawn when re-entering the room and champion enemies may not be there anymore.
This trick cannot be used to escape from Boss, Mini-Boss, or Challenge Rooms.
Closing the Gap
Have you ever been in the following situation and wished you had a flying upgrade?
No way to get to the chest right? Wrong!
This is something that I discovered completely by accident but it it turned out to be very useful. If you place a bomb next to a rock, the rock will explode and fill the gap allowing you to cross over. Here is how it looks like when you explode the rock:
And here is how it looks like when you leave and re-enter the room:
Look for Secret Rooms
There is no better way to use excess bombs than to look for Secret Rooms! We already covered how to find these rooms in their respective pages, so make sure you give them a good look:
Keys vs Bombs
Keys and bombs are both useful, but here is something you should keep it mind:
One key is more useful than one bomb, but a lot of bombs are more useful than a lot of keys.
While most of the time you won't have any control over what pickups you get, you should always follow this rule in cases of Item Shops or other cases where you do have control.
Manage Your Item Charges
Re-usable items (spacebar items) can only be used every specific amount of rooms (until they recharge), and so must be managed correctly. For example you should not active an item that boosts your damage if there are not enough rooms left for the item to recharge until the boss.
When entering shops sometimes you will see items with their price listed in red. This means that particular item is being sold at a 50% discount and should always be purchased if possible.
The best discount you can hope for is on items, which will be offered at 7 cents instead of 15.
Similarly to the previous point, the item Steam Sale will make all items be on sale. This is a very good investment to make early on in the game as it will allow you to get a lot more items from the Item Shops.
Beggars are Useful
Beggars are a sort of gambling game where you give them money and with each coin there is a chance they will drop something. On average you can get an item for much less than 15 cents (which is what they cost from the shop), so always give this guy a go when possible. At the very least you will have gotten some pickups or a Tarot Card.
Tinted Rocks looks like regular rocks but have a bluish hue to them. These rocks are special in that when you explode them they give the player a reward ranging from Soul Hearts to even an item. They are pretty easy to spot once you know what to look for.
Poo and Fireplaces
Most people ignore these but I have found that destroying each one pays off in the long run. Poos and Fireplaces are found all over the place and once destroyed have a chance of dropping random pickups. It costs nothing to destroy these objects so make sure you do it when possible.