BuxbrewResist: Overview

BuxbrewResist

See what your resistance stats could mean in combat. BuxbrewResist adds estimated damage reduction and partial-resist chances to the resistance tooltips in your character panel. You can also check your stats in chat with /buxres.

Designed for the WoW 1.12 client.

Installation

1. Exit the game completely. If you already copied the addon while the game was running, close the game and start it again.

2. Place the BuxbrewResist folder inside your game's Interface\AddOns folder. The files should be directly inside it:

   Interface\AddOns\BuxbrewResist\BuxbrewResist.toc
   Interface\AddOns\BuxbrewResist\BuxbrewResist.lua
   

3. Start the game. At character selection, click AddOns and make sure BuxbrewResist is enabled.

4. Log in and open your character panel to try it.

Installing a new addon requires a full game restart. /reload refreshes addons the client already knows about; it does not make a newly installed addon appear. Logging out to character selection is not enough either.

If BuxbrewResist is missing from the AddOns list, check that you installed it in the same game folder you launch and that there is no extra folder around it (such as BuxbrewResist\BuxbrewResist\BuxbrewResist.toc). Then restart the game.

For edits to the Lua code of an addon that is already loaded, /reload is enough. After installing an update, a full restart is the simplest way to ensure all changes are picked up.

Using the addon

Open your character panel (normally C) and hover over Arcane, Fire, Nature, Frost, or Shadow resistance. BuxbrewResist adds a section below the normal game tooltip. Stats are read each time you hover, so move your mouse away and back after changing gear or buffs.

The added section shows:

• Resistance-only average reduction: the estimated damage reduction across many spells, highlighted in green. It does not mean every spell loses that much damage.
• Damage reduced per spell / Chance: the estimated chances of taking full damage or resisting 25%, 50%, 75%, or all of a spell's damage.
• Total gain from +10 resistance: how much the total estimated average would increase with another 10 resistance. This is a percentage-point gain: going from 20% to 23% is a gain of 3 points, shown as +3%.
• Total vs level +3: the combined estimate against an attacker three levels above you, using a 1% base spell-miss assumption.
• Base spell miss (assumed): 4% against a same-level caster with no spell-hit bonuses.
• Total expected average reduction: resistance plus base misses, highlighted at the bottom. Even at 0 resistance, this total is 4%.
• Resistance cap: the cap used by the model against an attacker of your level, followed by how much more resistance you need to reach it.

The main estimate assumes an attacker at your level. Negative resistance shows a negative reduction in red, plus an Extra damage taken (estimate) row. For example, at level 60, -30 Fire resistance gives an estimated -10% reduction: a 100-damage Fire hit would become 110 damage before other modifiers. The partial-resist table is hidden while resistance is negative.

Chat commands

Available names are physical, holy, fire, nature, frost, shadow, and arcane. Capitalization does not matter. Unique prefixes such as sh also work; use fi or fr to distinguish Fire from Frost. Physical and Holy have separate summaries rather than the magic partial-resist breakdown.

Understanding the estimates

Direct damage, DoTs, and spells that resist completely

Direct damage happens in a hit: a warlock's Shadow Bolt is a non-binary example, meaning its damage can be partially resisted. When a spell allows partial resistance, only part of that damage may get through: a 1,000-damage hit with a 25% partial resist deals 750 damage.

Damage over time (DoT) happens in ticks, like a warlock's Corruption. There are two different questions: did the spell land, and how much damage does a tick deal afterward? A 100-damage tick with a 25% partial resist deals 75. That illustrates the outcome, not its chance. Tick rules depend on the spell, so the addon does not present one universal DoT percentage.

Binary means an all-or-nothing resistance check. A mage's Frostbolt is a Classic-reference example because it combines damage with a slow: the spell lands or is rejected, rather than having its initial effect partially reduced. Being a DoT or a direct spell does not by itself tell you all its resistance rules. The Classic reference also treats ticks from binary spells specially; this addon does not have a verified model for each spell.

A spell can fail at 0 resistance. The separate spell-hit check can also produce a “Resist” message in Vanilla. The Classic baseline is 4% spell miss between equal-level opponents before spell-hit bonuses and other modifiers, normally with a 1% minimum. This is an example, not a prediction for every enemy. The addon includes the assumed baseline in its total estimate. Enemy spell-hit bonuses and special spell rules are unknown, so this is an assumed scenario, not a measurement of your current opponent.

The tooltip keeps the numbers compact and puts the combined total at the bottom; explanations and spell examples are in chat. Use /buxres fire, /buxres shadow, or another school name for the full guide: your current estimates, a worked 1,000-damage example, the gain from +10 resistance, a comparison against a higher-level attacker, resistance caps, tick examples, binary checks, and spell misses. Negative resistance gets the same explanation alongside the red vulnerability estimate. Examples exclude crits, absorbs, and other damage modifiers.

The total includes base spell misses

The direct-damage total is miss + (1 - miss) * resistanceAverage. This layers base misses onto the addon's existing approximation without counting avoided damage twice. It is not simply resistance reduction plus four percentage points.

At level 45 with 42 Fire resistance, the resistance-only estimate is 11.25%. With the assumed 4% base miss chance, the total is 14.8%: an incoming 1,000-damage cast averages 852 damage, compared with 960 from base misses alone. At level 60 with -30 resistance, the -10% vulnerability estimate combines with misses to give -5.6% total reduction (1,056 damage per 1,000-damage cast), shown in red.

The +10 comparison, higher-level comparison, and chat overview also use totals. The resistance buckets remain resistance-only. The same-level cap is still a resistance cap; adding misses does not change it. The combined direct-damage estimate is not a universal DoT or binary-spell formula. Binary rejection in chat follows the Classic reference's combined failure roll (base miss plus the resistance contribution, capped at 100%).

How the numbers are calculated

These numbers come from a legacy approximation, not measured server probabilities. Treat them as a guide when comparing resistance values, not a guarantee of what the next spell will do. The binary-spell estimate in detailed chat output refers to an all-or-nothing resist model; it should not be read as a universal chance for every damage-over-time or crowd-control spell.

For readers interested in the calculation, the model starts with min(0.75, max(0, resistance / (5 * max(attackerLevel, 20)) * 0.75)), builds a distribution of partial-resist outcomes, and weights each outcome by its chance. The displayed average can differ from that starting value. Chat, tooltips, and the +10 comparison use the same weighted-average calculation.

Implementation references:

For negative resistance, the vulnerability estimate is resistance / (5 * max(playerLevel, 20)). This follows the CMaNGOS Classic reference implementation: it uses your level and does not apply the positive-resistance formula's 0.75 multiplier. Actual server behavior has not been verified. The same negative estimate is used in tooltips and chat.

• Vanilla character resistance tooltip scripts
• CMaNGOS Classic resistance implementation, CalculateEffectiveMagicResistancePercent and CalculateSpellResistChance. This is a reference implementation, not confirmation of actual server behavior.

Screenshots

Nature resistance:

Nature resistance tooltip showing average damage reduction and resist chances

Shadow resistance:

Shadow resistance tooltip showing average damage reduction and resist chances

Evidence and status

Reviewed on 2026-10-26 against main at 0691901. Current Lua, TOC, README and dated commit history were inspected. Source describes implementation; it does not establish successful operation. Historical intent is reconstructed only where labeled. No in-client test or automated test was executed during this documentation pass.

Documentation

• Concept · Design · Content
• Architecture · Decisions
• Roadmap · Changelog · Development journal
• AI collaboration · Contributor instructions

Document information

Author: Babuni.dev