As is most things in the game, your items will tell you how you should approach your strategy against Isaac. I've had bomb tears, lazers, rapid fire tears, etc. and took a very different approach each time.

General hints:

For Isaac's first form he shoots 12 radial tears. You are safe near the corners of the room. He also shoots retaliatory tears in an arc like the blood tears Monstro shoots, some might go short, some might go over you, so look for the shadows to where to dodge them. I generally just keep spinning in circles around Isaac shooting him and dodge the shadows when necessary.

His second form he shoots homing purple tears and shoots tears when hit. Again, circle around him, dodging tears when necessary.

When he starts spawning the angel babies (3rd form) that's when I usually pull out my consumables. Use your death card, my little unicorn, bombs, etc. Use em if you got em!

Wiki link: Isaac (Boss)

As is most things in the game, your items will tell you how you should approach your strategy against Isaac. I've had bomb tears, lazers, rapid fire tears, etc. and took a very different approach each time.

General hints:

For Isaac's first form he shoots 12 radial tears. You are safe just above or below the room's center left/right (see this video). He also shoots retaliatory tears in an arc like the blood tears Monstro shoots, some might go short, some might go over you, so look for the shadows to where to dodge them. I generally just keep spinning in circles around Isaac shooting him and dodge the shadows when necessary.

His second form he shoots homing purple tears and shoots tears when hit. Again, circle around him, dodging tears when necessary.

When he starts spawning the angel babies (3rd form) that's when I usually pull out my consumables. Use your death card, my little unicorn, bombs, etc. Use em if you got em!

Also, since Isaac pauses between active attacks, it's possible to drop bombs around him with relative safety while circling him. This has an added bonus of possibly killing some of the spawned baddies he creates in his 3rd form.

Wiki link: Isaac (Boss)

As is most things in the game, your items will tell you how you should approach your strategy against Isaac. I've had bomb tears, lazers, rapid fire tears, etc. and took a very different approach each time.

General hints:

Isaac's first form he shoots radial tears but keep in mind they are not all going to hit you, think the blood tears Monstro shoots. Isaac's tears are like Monstro's. He shoots a spray of tears but some might go short, some might go over you, look for shadows. I generally just keep spinning in circles around Isaac shooting him and dodge the shadows when necessary.

His second form he shoots homing purple tears and shoots tears when hit. Again, circle around him, dodging tears when necessary.

When he starts spawning the angel babies (3rd form) that's when I usually pull out my consumables. Use your death card, my little unicorn, bombs, etc. Use em if you got em!

Wiki link: Isaac (Boss)

As is most things in the game, your items will tell you how you should approach your strategy against Isaac. I've had bomb tears, lazers, rapid fire tears, etc. and took a very different approach each time.

General hints:

For Isaac's first form he shoots 12 radial tears. You are safe near the corners of the room. He also shoots retaliatory tears in an arc like the blood tears Monstro shoots, some might go short, some might go over you, so look for the shadows to where to dodge them. I generally just keep spinning in circles around Isaac shooting him and dodge the shadows when necessary.

His second form he shoots homing purple tears and shoots tears when hit. Again, circle around him, dodging tears when necessary.

When he starts spawning the angel babies (3rd form) that's when I usually pull out my consumables. Use your death card, my little unicorn, bombs, etc. Use em if you got em!

Wiki link: Isaac (Boss)