伤害是从某个实体的当前生命值中所减去的生命值的量。有众多实体都可以造成它，最显著的是武器、敌怪、和NPC（以及所有相关的射弹）。此外，它也可能是由环境危险（例如多刺灌木、机关、或熔岩）和游戏机制（例如掉落伤害、溺水、或减益）所造成的。通常只能对具有生命值属性的实体造成伤害，即玩家、大多数敌怪、和 NPC。大多数伤害还会对受伤害的实体造成击退。
当实体受到伤害时，在伤害实际应用于实体之前，会执行若干增减伤害量的计算（取决于多个因素；参见下文）。因此，任何造成伤害的实体的伤害属性数据通常都只是其所造成的平均伤害。大多数打击的伤害都会偏离此平均值。
Damage inflicted by player-wielded weapons is categorized into five different types: melee, ranged, magic, summon, and throwing. Accessories, buffs, and other damage-boosting or damage-decreasing effects often only affect one of these damage types. A few weapons as well as all other damaging entities are not categorized into any of the five types.
伤害类型
近战
近战武器用于近程至中程战斗。它们的主要特征是使用时不消耗弹药或魔力。它们大致分为剑、矛、连枷、回旋镖、和悠。还有其他几种近战武器不属于这些类型。
In total, there are currently 184 unique melee weapons.
远程
Ranged weapons are used in long-ranged combat. Their defining trait is the requirement of ammunition in order for the weapon to operate. They are roughly categorized into bows, repeaters, guns, and launchers. Note that Terraria classifies boomerangs as melee weapons and consumables as thrown weapons.
In total, there are currently 90 unique ranged weapons. On the 
tModLoader version, the total number is only 89 due to the differentiation of throwing weapons.
魔法
魔法武器用于中程至远程战斗。它们的主要特征是每次使用时都会消耗魔力。由于它们有非同寻常的独特攻击形式，大部分魔法武器都难以对其进行分类。
In total, there are currently 76 unique magic weapons.
召唤
Summoning weapons include summon staffs and whips. Using a summon staff spawns a secondary character which will aid the player in battle by automatically attacking enemies. The summoned character is either mobile, i.e. following the player around (minion), or stationary, i.e. remaining at the location it was summoned at (sentry). [[鞭|]] are close- to mid-range weapons which boost minion damage on hit enemies as well as marking them, making minions focus on those enemies.
Mounts that do damage, like the Slime Mount, deal summon damage.
In total, there are currently 46 unique summon weapons, 8 of which are whips.
投掷
投掷武器用于中程战斗。它们的主要特征是它们通常会在使用时被消耗掉。它们在玩家的物品栏会堆叠，每次用于攻击时都会从堆叠中移除一个单位，在最后一个单位都被用掉后留下空栏位。许多投掷武器在使用后都有回收的机会。
Throwing is only considered a separate damage type on the tModLoader version. Throwing weapons deal ranged damage instead on the 
Desktop version, 
Console version, 
Old-gen console version, 
Mobile version, Nintendo 
version, and 
Nintendo Switch version. In total, there are currently 4 unique throwing weapons.
Invincibility frames and piercing
Player invincibility
受到伤害后，玩家会得到一段称为“无敌帧”的时间，在此期间他们就不会再次受到伤害。默认情况下是 2/3 秒（40 嘀嗒[1]），但有各种装备可以延长之：
- 使用十字项链或其任意升级物会在受到攻击后再加上 2/3 秒（40 嘀嗒）。（十字项链与其升级物不叠加。）
- 如果穿上黑腰带（或其升级物忍者大师装备，但二者不叠加），成功的躲闪（10% 几率）会触发无敌帧并为其加上 2/3 秒（40 嘀嗒）。Verify它同样还会防止此攻击造成伤害（但不会防止与其相关的减益）。如果将其与十字项链组合，这能将无敌延长至整整 2 秒（120 嘀嗒）。
- Hallowed armor similarly provides the Holy Protection buff; this is triggered by attacking an enemy, and when active, the next time the player would have taken damage, they instead get 2 seconds (120 ticks) of invincibility. This also stacks with the effects of the Cross Necklace and Black Belt, potentially granting 3 and 1/3 seconds (200 ticks) of invincibility.
Piercing attacks against enemies
敌怪能从“穿透”和持续攻击（任何可以击中敌怪并在随后依然能够造成伤害的伤害源）中得到类似但更有限的效果。
在受到这种攻击后，此敌怪在短时间内就不再会从另一个此类攻击中承受伤害，这个时间通常为 1/6 秒（10 嘀嗒[1]）。因此，在熔岩中或者被魔刺之类的持久性武器刺穿时，它们每秒最多承受 6 次伤害。但是，对于多体节的敌怪（通常是蠕虫类），此抗性是分别作用于每个体节的，因此此类攻击以然可以击中单个敌怪的多个体节。（请注意，任何情况下蠕虫类敌怪都是免疫熔岩的。）
On the Old-gen console version, Nintendo version, and tModLoader versionVerify, this also applies to almost any missile, beam, or other attack which can pass through an enemy to strike other enemies behind it. This can sharply limit the effects of rapid-fire guns and bows, and those which fire multiple projectiles. Most minions are considered to have piercing attacks, which can also hinder the efficiency of piercing weapons used alongside them. This problem is remarkably present with the Spider Staff and the Stardust Dragon Staff.
一些高级武器具有特殊行为：
计算
玩家挥舞的武器命中时所造成的伤害是按以下方式累计得出：
- 步骤 1：应用武器修饰语
- 中间值1 = 基础伤害值 * (1 + 武器修饰语/100)
- 步骤 2：取整，四舍五入到最接近的整数
- 中间值2 = 四舍五入(中间值1)
- 中间值3 = 中间值2 * [1 + (头部 + 胸部 + 腿部 + 套装加成)/100 + (配饰1 + 配饰2 + .. + 配饰5 + 配饰修饰语1 + 配饰修饰语2 + .. + 配饰修饰语5)/100 + (增益1 + 增益2+ ..)/100]
- 注意：对于远程武器计算会略有不同，箭/子弹/火箭的伤害是和其他修正相乘计算的（每步计算后都向下取整），所以大致是这样：
- 中间值3 = (中间值2 + 箭/子弹/火箭) * [1 + (头部 + 胸部 + 腿部 + 套装加成)/100 + (配饰1 + 配饰2 + .. + 配饰5 + 配饰修饰语1 + 配饰修饰语2 + .. + 配饰修饰语5)/100 + (增益1 + 增益2+ ..)/100]
- 步骤 4：向下取整
- 武器伤害 = 中间值4 = 向下取整(中间值3)
- 武器伤害 = 向下取整(1.2*中间值 4)
举个例子，神级 太极连枷加上装备着海龟盔甲、险恶 战士徽章、险恶 复仇者徽章, 险恶 毁灭者徽章、险恶 机械手套和险恶 天界石，吃得好处于激活状态：
中间值1 = 63 * (1 + 14/100) = 71.82
中间值2 = 四舍五入(71.82) = 72
中间值3 = 72 * [1 + (6+8+0+0)/100 + (15+12+10+12+10+4+4+4+4+4)/100 + (5)/100] = 72 * [1.98] = 142.56
武器伤害 = 向下取整(142.56) = 142
小心：这里只能用那些对具体武器有影响的修饰语（例如，不要把魔法伤害奖励用到近战武器上）。
对敌怪实际造成的伤害则取决于敌怪的防御力以及附近是否有相关的敌怪旗。
- 敌怪伤害减免 = 向上取整(敌怪防御力 * 0.5)
所以，
- 无敌怪旗时：对敌怪造成伤害 = 武器伤害 - 敌怪伤害减免
- 有敌怪旗时，普通模式下：对敌怪造成伤害 = 1.5*武器伤害 - 敌怪伤害减免
- Or DamageDealtToEnemy = 2*WeaponDamage-EnemyDamageReduction with a banner in Expert Mode,
实际造成的伤害最少是 1。
另外，实际出去的伤害还会用一个随机系数修正一下，系数随机取值范围为 0.85~1.15，（但某些类型的伤害，比如史莱姆坐骑，不受此项影响），结果最后四舍五入取整至最接近的整数。所以可以计算出你的武器对敌怪的最小和最大伤害：
- 最小伤害 = 四舍五入(武器伤害 * 0.85 - 敌怪伤害减免)
- 最大伤害 = 四舍五入(武器伤害 * 1.15 - 敌怪伤害减免)
暴击时你会造成双倍伤害
- 最小暴击伤害 = 最小伤害 * 2
- 最大暴击伤害 = 最大伤害 * 2
注释
Template:游戏机制