Isaac's tears decelerate as they travel. Upon stopping or hitting an obstacle, they burst into 8 tears in all directions. Tears can be fired into other tears to feed them, increasing their damage.
Quote
"Feed them!"
Effects
Isaac's tears decelerate as they travel. Upon stopping or hitting an obstacle, they burst into 8 tears in all directions.
Hitting an enemy will not cause them to burst.
Tears can be fired into other tears to feed them, increasing their damage and the damage of the burst tears.
If one tear is fed 5 other tears, it will immediately burst.
The tears will have their damage added together, with the first consumed tear giving additional damage.
Tears in the burst will deal half the damage the main tear would have.
Tear bursting can also happen from sheer shot size. With sufficiently high damage or several tear-size increasing items, the tears will burst almost immediately after firing.
Synergies
20/20 - Tears tend to clump together soon after firing for high damage shots. It may take more than 5 tears in total to cause a burst.
The Inner Eye - Tears tend to clump together soon after firing for high damage shots. It may take more than 5 tears in total to cause a burst.
Mutant Spider - Tears tend to clump together soon after firing for high damage shots. It may take more than 5 tears in total to cause a burst.
Compound Fracture - Bone tears split into a random spread of fractured tears and bone tears.
Euthanasia - Needle shots will allow the tears to burst at least twice.
Haemolacria - Tears look like Hameolacria. They can be fed and will burst into 8 tears that have Haemolacria's burst effect upon hitting obstacles or enemies.
A Lump of Coal - Tears continually grow in size without being fed other tears, but they will still only deal bonus damage based strictly on how far they travel. Burst tears will still grow in size and damage as they travel.
Monstro's Lung - The tears clump together soon after firing, causing potentially up to 20x tear damage on a direct hit on an enemy.
Lead Pencil - The tears clump together soon after firing, causing potentially up to 20x tear damage on a direct hit on an enemy.
Pulse Worm - The fluctuating hitboxes of the tears causes them to clump together at a faster rate.
Sinus Infection - Boogers will always burst into more boogers, though some of the boogers may incorrectly appear to be normal tears. When a booger sticks to an enemy, it will burst into 8 boogers which have a high chance of sticking again to the same enemy.
Tractor Beam - All split tears will travel along the beam. Split tears are no longer confined to the beam.