Dodge

When a dodge fires, the attack does not connect at all. The damage does not happen, the knockback does not happen, and any debuff the attack would have applied does not get inflicted. That is a different category from defense, which only shaves a number off the top, and from immunity frames, which just space incoming hits further apart. A dodge is the closest thing in the game to the hit never having been thrown.

Almost anything that hits you directly is eligible. Enemy contact, enemy projectiles, spike traps, thorny bushes, lava, even a fall you should not have survived. The rule for what is exempt is simple once you see it: if something damages you without an attack landing, there is nothing to dodge.

So poison, burning and every other damage-over-time debuff tick straight through. Drowning goes through. The Horrified kill you take for trying to run from the Wall of Flesh goes through, as does the Chaos State penalty from using the Rod of Discord too often. A short list of specific enemy attacks is also flagged undodgeable in code, so treat dodging as insurance on most of the fight rather than a guarantee on all of it.

The effects are ordered by priority, and the first one that succeeds is the only one that spends itself. If the Black Belt rolls its chance, a banked Holy Protection charge is not consumed on that same attack, it stays available for the next one. That ordering is what makes stacking worth thinking about instead of just piling on sources.

Brain of Confusion does stack with the ninja line, and together they negate one attack in four on average. What does not stack is the belt with Master Ninja Gear, because the gear already contains it. Wearing both wastes a slot outright, so once you can craft the upgrade, feed the belt into it and use the free slot for something else.

Every successful dodge hands you 1.33 seconds during which nothing at all can touch you, and that stretches to a full 2 seconds with a Cross Necklace or Star Veil equipped. In a crowded fight that window is often worth more than the negated hit, because two seconds is long enough to walk out of a swarm or cross a curtain of projectiles that would otherwise have cost you three more hits.

Reflect damage still goes out during a dodge. The Thorns buff and the reflect bonuses on the Turtle and Cactus sets all fire normally on an attack you took nothing from, which is the one case where being hit is strictly free.

Defense scales badly against big single hits. Against something that removes a third of your bar per contact, another five points of defense changes almost nothing about how many hits you survive, while a one in four chance to erase the hit entirely changes the math on every exchange. That gap widens the higher the difficulty goes, and in Master Mode it is the difference between a fight being possible and not.

It is also the right answer to bosses that flood the screen. Fast movers and projectile spammers give you many chances to roll the dodge, and each success buys immunity frames on top, so the busier the fight, the more the effect compounds. Against a slow boss that hits once every few seconds you will barely notice it.