How Rare Rings Are Made

This document explains how Diablo II: Resurrected generates rare and crafted rings, from affix selection mechanics to the scoring system used by this tool. If you've ever wondered why some rings are godly and others are charsi food, the math is here.

Table of Contents

• How a Rare Ring Is Generated
• Affix Count Distribution
• Prefix and Suffix Split
• Group Selection
• Tier Selection Within a Group
• Value Rolling
• Item Level and Affix Level
• Mutual Exclusivity
• Special Display Rules
• Crafted Rings
• The PvM Scoring System
• What Makes a Trophy Ring

How a Rare Ring Is Generated

When a rare ring drops in Diablo II, the game builds it through a multi-step process. Each step involves weighted random selection that determines how many affixes the ring gets, which affix groups are chosen, which specific tier within each group is picked, and what value is rolled within that tier's range.

The entire pipeline looks like this:

1. Determine the total number of affixes (3 to 6)
2. Split that total into prefixes and suffixes
3. For each slot, select an affix group (weighted by frequency)
4. Within the chosen group, select a specific tier (weighted by frequency)
5. Roll a value uniformly within that tier's min–max range

Every step is independent and random. There is no pity system, no streak protection, and no hidden bias toward "better" rings.

Affix Count Distribution

Rare rings always have between 3 and 6 affixes total (prefixes + suffixes combined). The distribution is not uniform — it follows a 1:2:3:2 ratio:

Five-affix rings are the most common outcome. Three-affix rings are quite rare. This distribution alone means that a six-affix ring (the maximum, and a prerequisite for the highest scores) only occurs one in four times.

Prefix and Suffix Split

Once the total affix count is determined, the game splits it into prefixes and suffixes. Each affix has a 50/50 chance of being a prefix or suffix, subject to the hard cap of 3 prefixes and 3 suffixes maximum.

This is modeled as a binomial distribution with rejection of invalid splits. For example, with 5 total affixes:

The 0+5 and 1+4 splits would violate the 3-max rule, so they're excluded and the remaining valid splits are renormalized. For 6 affixes, the only valid split is 3+3 (100%).

Group Selection

Every ring affix belongs to a group. A group contains all tiers of a single property — for example, group 110 contains Bronze (+10–20 AR), Iron (+21–40 AR), Steel (+41–60 AR), Silver (+61–80 AR), Gold (+81–100 AR), and Platinum (+101–120 AR). Only one affix per group can appear on a ring.

When selecting a prefix or suffix, the game:

1. Gathers all available groups for that affix type
2. Assigns each group a weight equal to the sum of all its tiers' Frequency values
3. Selects groups without replacement, weighted by these sums

A group with more tiers or higher-frequency tiers is more likely to be chosen. For prefixes, the Attack Rating group (110) has a combined frequency of 42 across its six tiers, while the Mana after Kill group (121) has a frequency of just 4 — making AR roughly ten times more likely to be selected as a prefix.

Prefix Groups on Rings

Suffix Groups on Rings

FCR (of the Apprentice) is a single-tier group with frequency 6. It competes against 20 other suffix groups for selection. On any given suffix slot, the chance of landing FCR is roughly 6 out of the total suffix pool weight (~165), or about 3.6% per suffix slot.

Tier Selection Within a Group

Once a group is selected, the game picks a specific tier within it. Each tier has its own Frequency value, and selection is weighted by these individual frequencies.

Using Attack Rating (group 110) as an example:

Higher tiers tend to have slightly lower frequency, making them marginally rarer. The difference is modest — Platinum is only about 25% less likely than Bronze within the group.

Value Rolling

After a tier is selected, the game rolls a value uniformly at random within that tier's range. Every value in the range is equally likely. For Platinum Attack Rating (+101 to +120), each specific value from 101 to 120 has a 1/20 (5%) chance.

This is where the scoring system's thresholds create interesting boundaries. A Platinum roll of 101 scores the same as 120 under PvM scoring (both are 1.0 points), but a Gold roll of 80 also scores 1.0 while 79 only scores 0.5. The tier boundaries in the game data don't always align with scoring thresholds.

Item Level and Affix Level

Every affix tier has a minimum affix level (alvl) that determines when it enters the selection pool. The alvl available on an item is derived from the item level (ilvl), which comes from the monster that dropped the ring or the gambling formula.

The key mechanic is clobbering: when two tiers in the same group share the same name but have different affix levels, the higher-alvl version replaces the lower one once the ilvl is high enough. This is not a display quirk — the lower tier is literally removed from the selection pool.

How Clobbering Works

The Mana prefix group (115) demonstrates this clearly. The two lowest tiers are:

Both share different names here, but consider Rugged in the Stamina group (109):

Both are called "Rugged" but they are distinct affix entries with different ranges and affix levels. At ilvl 1–7, only the first Rugged (+5–10) can appear. Once ilvl reaches 8, the second Rugged (+11–20) becomes eligible and replaces the first in the pool. A high-level character can never see +5–10 Stamina on a ring because the +11–20 version has clobbered it.

This clobbering mechanism exists throughout the affix tables. It means that at endgame item levels, the pool of available affixes is different from what low-level characters see — some weak affixes are simply gone, replaced by their stronger counterparts.

Practical Impact

For endgame players gambling or finding rings in Hell difficulty, ilvl is typically high enough that all top-tier affixes are available and all clobbered tiers are gone. The generator assumes this scenario — all affix tiers are available at their maximum potential — since it's designed for evaluating endgame ring quality.

The required level displayed on each affix tier in the generator reflects the character level needed to equip a ring with that affix, not the ilvl needed to find it.

Mutual Exclusivity

The group system enforces mutual exclusivity: only one affix from each group can appear on a ring. This has several important consequences:

• You cannot have both Cold Resistance and another Cold Resistance tier (they're all group 117)
• You cannot have two different charged skills (they're all group 44)
• You can have both a prefix Magic Find (Felicitous, group 114) and a suffix Magic Find (of Chance, group 22) because they're in different groups
• You can have both a prefix Light Radius (Glimmering, group 112) and a suffix Light Radius (of Light, group 25) for the same reason

This prefix/suffix group independence is why some rings can roll double MF or double Light Radius — they're mechanically different affixes that happen to modify the same stat.

Special Display Rules

The game applies several display-time transformations that combine or reformat affix lines:

Resistance Fan-Out

When All Resistances (group 116) coexists with any individual resistance on the same ring, the game fans out the all-resist value into four individual lines and combines them with any matching single resists. A ring with Rainbow (+11 all) and Cobalt (+30 cold) displays as:

• Cold Resist +41%
• Fire Resist +11%
• Lightning Resist +11%
• Poison Resist +11%

When All Resistances appears alone, it displays as a single line: "All Resistances +11".

Stat Merging

When a prefix and suffix modify the same stat (Magic Find or Light Radius), the game combines them into a single display line. A ring with Felicitous (+10% MF) and of Chance (+15% MF) shows one line: "+25% Better Chance of Getting Magic Items".

Light Radius Secondary Effect

The suffix Light Radius group (of Light, of Radiance, of the Sun) has a hidden secondary effect: it also grants Attack Rating. This bonus varies by tier:

The flat AR bonus (+15/+30) stacks with any prefix Attack Rating on the ring. The percent AR bonus (+5% from of the Sun) is a separate stat that displays as its own line.

Crafted Rings

Crafted rings are created through the Horadric Cube using a specific recipe (ring + jewel + gem + rune). They differ from rare rings in several ways:

Affix Count

Crafted rings always have exactly 4 random affixes (compared to 3–6 for rare). The prefix/suffix split follows a weighted distribution:

Guaranteed Craft Bonuses

In addition to the 4 random affixes, every crafted ring receives 3 guaranteed bonuses specific to its type. These bonuses are rolled independently and stack with any matching random affixes:

Blood Ring (Ral + ring + perfect ruby + jewel):

• +1–3% Life stolen per Hit
• +10–20 to Life
• +1–5 to Strength

Caster Ring (Amn + ring + perfect amethyst + jewel):

• Regenerate Mana 4–10%
• +10–20 to Mana
• +1–5 to Energy

Hit Power Ring (Fal + ring + perfect sapphire + jewel):

• +1–5 to Dexterity
• 5% Chance to cast Level 4 Frost Nova when Struck
• Attacker Takes Damage of 3–6

Safety Ring (Nef + ring + perfect emerald + jewel):

• +1–5 to Vitality
• Magic Damage Reduced by 1–2
• Damage Reduced by 1–4

Craft Bonus Stacking

When a craft bonus matches a random affix (e.g., Blood ring rolls of the Leech for life leech, and also gets the guaranteed +1–3% life leech craft bonus), the values combine into a single line on the item. A Blood ring with of the Locust (+5% leech) and a craft roll of +3% would display as "+8% Life stolen per Hit".

This stacking is purely additive and happens at display time. For scoring purposes, the random affix and craft bonus are evaluated on their combined total.

Craft Scoring Ceiling

Of the four craft types, only Blood has a guaranteed bonus that can independently reach a PvM scoring threshold: its +10–20 Life bonus can hit the 0.5-point threshold (14+) when combined with a Life suffix roll, or on its own with a roll of 14+. The other craft bonuses (Strength +1–5, Regenerate Mana, Energy, Dexterity +1–5, Vitality, damage reduction) all fall below their respective scoring thresholds.

This makes 4.5 the theoretical maximum PvM score for a crafted ring (4.0 from four perfect random affixes + 0.5 from the Blood life bonus). In practice, crafted Blood rings are valued more for their raw stat totals — a Blood ring with high life, high strength, and FCR can be extremely powerful even at a modest PvM score, because the craft bonuses add flat value that the scoring system doesn't fully capture.

The PvM Scoring System

The PvM scoring system evaluates ring quality for Player vs Monster (farming) builds. Each affix is scored independently on its rolled value, using a two-tier threshold system:

Scoring Thresholds

Prefixes:

Suffixes:

Properties not listed (Energy, Stamina, Gold Find, Light Radius, charged skills, etc.) score 0 regardless of their rolled value. They occupy an affix slot without contributing to the PvM score.

Score Tiers

Scoring Independence

Each affix is scored on its own rolled value, not on combined totals. If a ring has Rainbow (+8 all resist, scores 1.0) and Cobalt (+25 cold resist, scores 1.0), that's 2.0 points from resistances — even though the displayed cold resist is +33%. The scoring reflects the quality of each individual roll, not the visual sum.

What Makes a Trophy Ring

A 6.0-point ring requires six affixes that each score 1.0. This means:

1. The ring must roll 6 total affixes (25% chance)
2. The split must be 3+3 (the only valid split for 6 affixes)
3. All 3 prefixes must be scoring prefixes with high-tier rolls
4. All 3 suffixes must be scoring suffixes with high-tier rolls
5. Every individual value must land in the 1.0-point threshold

The probability of each step compounds multiplicatively. Even after getting 6 affixes, the chance of all six landing scoring groups, high tiers, and high rolls is vanishingly small. Monte Carlo simulations of millions of rare rings consistently show 6.0+ rates in the range of roughly 1 in 100,000 rare rings.

To put that in perspective: if you gamble roughly 300 rings per 10 million gold, you'd need on the order of 3 billion gold and over 160 hours of dedicated gambling to expect a single 6.0 ring — and that's before considering that many of those "perfect" combinations might not be the specific stats you want.