Samson

Samson is a character unlocked by beating two floors in a row without taking any damage. Samson starts with 3 Red Heart containers and Bloody Lust.

Samson will also start with Child's Heart after completing the Ultra Hard challenge.

Notes

Due to Samson's starting item, Bloody Lust, he has a playstyle that is similar to Eve. Therefore, health sacrifices such as Devil Beggars, Sacrifice Rooms, and Blood Donation Machines are recommended.
- As a result, anything that lowers health is not recommended, as that will make self-damage less effective. Angel Rooms are more valuable than Devil Rooms, if the player comes across any.
The first three times Samson is hit, his damage is increased by 0.5. The next three times Samson is hit, his damage is increased by 33%.
Damage is increased by flat amounts: +0.5 for the first hit and an additional +0.2 for each hit, until +1.5 at the sixth. This means that the maximum total is +6.0.
Samson's starting trinket, Child's Heart, is one of the more optional unlocks — the trinket itself is not too powerful, not to mention it requiring the completion of the Ultra Hard challenge.
When Samson dies in co-op, his ghost baby maintains his level of rage from Bloody Lust, giving it a red tint. This is purely visual.
Dying as Samson and then respawning as another character (with Lazarus' Rags, Ankh, etc.) will make them inherit Samson's Bloody Lust item.

Item Interactions

Birthright: Bloody Lust can gain 4 more damage boosts at the same +0.2 intervals, for a new maximum total of +14.0.

Favorable items

Any items that increase health so Samson can take more damage before dying.
Any items that increase Samson's tears stat, such as Squeezy, Odd Mushroom, etc.
Any items that generate Blue Flies, like Rotten Baby or Guppy's Head, do so based on Samson's base damage and are good for early game room clearing when Samson's tears are still low.
Items relying on contact damage, like The Virus or E. Coli, can be beneficial in that damage is desirable with Bloody Lust.
Health regeneration items like Yum Heart, Pyromaniac, and Placenta allow health regeneration after taking damage, and thus allow for more damage, both stat-wise and health-wise.
Old Bandage increases Samson's health while also providing a regeneration of sorts, allowing him to take much more damage.
Cancer and The Wafer minimize damage taken from Sacrifice Rooms and can be incredibly useful to build a lot of damage and pickups, especially in combination with an excess of hearts. The Wafer in particular is incredibly helpful in Chapter 4 and beyond, where all taken damage increases to one full heart per instance.
Dead Bird, Best Bud, Smart Fly, etc: All of these items will add to Samson's damage increase from getting hurt, although, unlike Bloody Lust, the bonus of these items only last for the duration of a room.
Fanny Pack's chance of dropping a heart upon hit can cancel out damage to Samson while also buffing him.
Dull Razor can safely provide Samson's damage boost without needing to take damage.
Gimpy increases benefits from taking damage and feasibly adds more survivability from random soul hearts and half-heart drops.
Immaculate Conception and Cambion Conception will produce familiars as Samson heals or receives damage, respectively.
IV Bag, Blood Rights, Razor Blade, Sharp Plug, Kamikaze!: Activating their effects also gives Samson a boost in damage since they deal self-damage.
Blood Oath is extremely useful on Samson, as its damage up effect stacks with Bloody Lust, granting a significant amount of damage up upon the start of a new floor.

Unfavorable items

Anything which lowers health, such as Dead Cat, can make purposeful self-damage less reliable as a damage booster. For this reason, taking items from the Devil Room or the Black Market, which cost health for every item thus taken, is not recommended for Samson.

Unlockable Achievements

Samson's Chains - Complete the Boss Rush as Samson.

Fighting Baby - Defeat Mom's Heart on Hard mode as Samson.

Blood Rights - Defeat Satan as Samson.

Bloody Lust - Defeat Isaac as Samson.

Samson's Lock - Defeat The Lamb as Samson.

Blood Penny - Defeat ??? as Samson.

Lusty Blood - Defeat Ultra Greed as Samson.

Stem Cell - Defeat Ultra Greedier as Samson.

Blind Rage - Defeat Hush as Samson.

Rage Baby - Defeat Mega Satan as Samson.

Bloody Crown - Defeat Delirium as Samson.

Bloody Gust - Defeat Mother as Samson.

Empty Heart - Defeat The Beast as Samson.

The Savage - Use Red Key (etc.) to open the hidden closet in Home as Samson.

Revenge Baby - Earn all Hard mode Completion Marks as Samson.

Unlockable Starting Items

Complete Ultra Hard (challenge #34) - Start with Child's Heart

Gallery

Samson's transition screen portrait.
The spawn floor when playing Samson.
Samson's locked character icon.

Trivia

In the Bible, Samson was a supernaturally strong warrior who derived his power from his Nazarite vow, entitling immense strength to Samson if he did not cut his hair.
Samson first appeared in the Binding of Isaac: Wrath of the Lamb expansion, where he was unlocked by skipping two Treasure Room items and killing Mom in one run.
- In that version, he had only 1 heart container and a soul heart for his starting health, and his Bloody Lust item acted as a weaker version of Afterbirth's Lusty Blood item.
Samson's locked icon shows him bound in chains.
- He shares this trait with Magdalene, Cain, Eve, Lazarus, Bethany, and Jacob and Esau.