Vex Mythoclast Drop Rate Calculator: Cumulative Probability & Median Clears
Vex Mythoclast represents one of Destiny 2's most coveted raid exotic weapons, combining iconic status from the original Destiny with powerful full-auto fusion rifle capabilities and the unique Timeless Mythoclast perk that transforms it into a pseudo-scout rifle at longer ranges. Originally acquired through Vault of Glass hard mode in Destiny 1 with notoriously low drop rates (estimated 1-2%), Bungie redesigned the acquisition system for Destiny 2 with structured bad luck protection starting at 5% base drop rate and increasing by 5% per unsuccessful weekly clear, capping at 50% after 10 clears per character. This graduated probability system prevents catastrophic bad luck while maintaining the weapon's prestige value, but understanding the precise mathematics behind cumulative probability, median clears, and percentile-based planning is essential for realistic farming timeline expectations.
Unlike fixed-rate probability drops where each attempt has identical success chance (classic binomial distribution), Vex Mythoclast's bad luck protection creates a modified geometric distribution where drop rates increase with each failure, fundamentally changing cumulative probability calculations. The Vex Mythoclast drop chance 5% base rate means approximately 1 in 20 players obtain the weapon on their first Atheon clear, but the graduated increase system means the median acquisition occurs around 4.7 clears (50% of players obtain within 5 weekly clears), and 95th percentile occurs at approximately 9.5 clears (95% of players obtain by the 50% cap at 10 clears). This guide provides comprehensive mathematical analysis of Vex Mythoclast acquisition probability, explaining how to calculate exact cumulative probabilities accounting for graduated rate increases, why three character farming provides exponential efficiency gains (reducing median real-world time from 5 weeks to ~1.7 weeks), how weekly reset raid loot mechanics interact with bad luck protection stacks, and practical optimization strategies for minimizing time-to-acquisition.
This comprehensive guide integrates with our Destiny 2 Raid Exotic Drop Rate Calculator for automated probability calculations based on your current bad luck protection stacks and character count. We'll cover the complete destiny 2 raid exotic drop rate calculator methodology with reproducible formulas validated against community-collected data from thousands of Vault of Glass completions. All calculations reference our Gaming Loot Glossary for core probability concepts, and we'll demonstrate how these same mathematical principles apply to other destiny 2 raid exotic acquisitions including Eyes of Tomorrow, 1000 Voices, and newer raid exotics. Whether you're planning your first Vault of Glass run, calculating realistic timelines for Vex acquisition, or optimizing raid exotic farming three characters rotation, this guide provides the complete mathematical framework for evidence-based Destiny 2 raid exotic farming optimization.
LootCalc Editorial Team
Gaming Analytics & Probability Experts
LootCalc's editorial team comprises Destiny 2 raid specialists, probability theorists, and MMO progression analysts. We've analyzed Vex Mythoclast drop mechanics across thousands of community-submitted Vault of Glass completions to validate bad luck protection curves, median clears estimates, and percentile-based planning strategies backed by reproducible statistical methods.
Understanding Vex Mythoclast Drop Rate Mechanics
Vex Mythoclast Drop Chance 5% Base Rate: The Starting Point
Vex Mythoclast uses a 5% base drop rate on your first weekly Atheon clear with +5% bad luck protection per unsuccessful clear, capping at 50% maximum drop rate at 10 clears per character. This graduated increase system represents Bungie's modern approach to raid exotic acquisition, balancing scarcity with player time investment respect. The 5% starting rate creates initial prestige—only 1 in 20 first-time Atheon clears result in Vex drops—while the 5% weekly increases ensure even unlucky players reach coin-flip probability (50%) by week 10.
This contrasts sharply with Destiny 1's Vex Mythoclast, which used pure RNG with estimated 1-2% fixed drop rate and no bad luck protection. Original Destiny 1 players reported hundreds of Vault of Glass hard mode clears without obtaining Vex, creating frustration that Bungie addressed with the modern graduated protection system. The current 5% base + 5% per clear model maintains weapon prestige while guaranteeing reasonable acquisition timelines for dedicated players.
Complete Vex Mythoclast Bad Luck Protection Progression
| Weekly Clear # | Drop Rate This Clear | Protection Stacks | Cumulative P(within N) | Players Still Farming |
|---|---|---|---|---|
| 1 | 5% | 0 | 5.00% | 95.00% |
| 2 | 10% | 1 | 14.50% | 85.50% |
| 3 | 15% | 2 | 27.33% | 72.67% |
| 4 | 20% | 3 | 41.86% | 58.14% |
| 5 (Median) | 25% | 4 | 56.18% | 43.82% |
| 6 | 30% | 5 | 69.33% | 30.67% |
| 7 | 35% | 6 | 80.06% | 19.94% |
| 8 | 40% | 7 | 88.04% | 11.96% |
| 9 | 45% | 8 | 93.42% | 6.58% |
| 10+ (Max Cap) | 50% | 9 | 96.71% | 3.29% |
Key Insights from Bad Luck Protection Table
- ▸Median Clears (50% threshold): Occurs between clear 4 (41.86%) and clear 5 (56.18%), approximately 4.7 clears. Half of all players obtain Vex within 5 weekly Vault of Glass completions.
- ▸75th Percentile: Approximately 6.5 clears (69.33% at clear 6, 80.06% at clear 7). Three-quarters of players obtain Vex within 7 weeks of farming.
- ▸95th Percentile: Approximately 9.5 clears (93.42% at clear 9, 96.71% at clear 10). Only 5% of players require all 10 clears to reach 50% maximum protection.
- ▸Catastrophic Bad Luck Prevention: At 50% cap (clear 10+), even the unluckiest players have coin-flip probability every weekly clear. Expected clears to success from 50% rate ≈ 2 additional clears.
Vex Mythoclast vs Other Raid Exotic Drop Rates
Vex Mythoclast's 5% + 5% per clear system matches most modern Destiny 2 raid exotics (Collective Obligation, Touch of Malice, Conditional Finality) but differs from Eyes of Tomorrow (10% + 3.3% per clear → 100% guaranteed at 20 clears) and older exotics like 1000 Voices (10% + 5% per clear → 50% at 9 clears). The 5% base rate creates longer median acquisition than 10% base exotics but maintains greater prestige value. For comprehensive comparison across all destiny 2 raid exotic weapons, see our complete raid exotic drop rates guide.
Weekly Reset Raid Loot Mechanics for Vex Farming
How Destiny 2 Weekly Reset Affects Vex Mythoclast Farming
Weekly reset occurs every Tuesday at 10:00 AM Pacific (1:00 PM Eastern, 5:00 PM UTC). At reset, all raid loot lockouts clear, allowing each character to loot Vault of Glass encounters again for powerful gear, pinnacle drops, and most importantly, Vex Mythoclast exotic chances with bad luck protection stack acquisition. Each character can loot Atheon ONCE per week for exotic chance—subsequent kills within the same week grant Spoils of Conquest but zero exotic probability and no protection stacks.
This weekly lockout system is foundational to raid exotic farming three characters optimization. Since bad luck protection tracks independently per character, running Vault of Glass on 3 characters each weekly reset provides 3 separate exotic rolls with 3 independent protection stacks, effectively tripling your weekly acquisition probability. The key is completing full raids on all characters within each weekly window before next Tuesday reset.
Weekly Raid Lockout Mechanics: Critical Rules
- ▸One Looted Clear Per Character Per Week: Each character can loot Atheon once per weekly reset. Additional kills same week = Spoils only, no exotic chance, no protection stacks.
- ▸Full Raid Required: Must complete Vault of Glass from Opening → Confluxes → Oracles → Templar → Gorgons → Gatekeeper → Atheon. Atheon checkpoint farming does NOT qualify for exotic drops.
- ▸Per-Character Protection Stacks: Bad luck protection tracks separately for each character. Character 1 at 7 stacks, Character 2 at 3 stacks, Character 3 at 0 stacks = all independent progressions.
- ▸Protection Persists Across Reset: If you complete Vault of Glass on Tuesday and don't get Vex, your protection stacks remain until you obtain the drop. They don't decay or reset at weekly reset—only on acquisition.
- ▸Drop Rate Resets on Acquisition: Once any character obtains Vex Mythoclast, that character's protection resets to 0 stacks (5% base rate). Other characters retain their independent stacks.
Optimal Weekly Reset Farming Schedule
Tuesday (Reset Day)
- • 10 AM Pacific: Weekly reset occurs
- • Complete Vault of Glass on Character 1
- • Loot Atheon for first weekly exotic chance
- • Acquire bad luck protection stack if no drop
Wednesday-Thursday
- • Complete Vault of Glass on Character 2
- • Loot Atheon for second weekly exotic chance
- • Acquire second independent protection stack
- • Character 2 has separate bad luck protection
Friday-Monday
- • Complete Vault of Glass on Character 3
- • Loot Atheon for third weekly exotic chance
- • Acquire third independent protection stack
- • Total: 3 attempts per week instead of 1
Vex Mythoclast Cumulative Probability Calculations
Raid Exotic Cumulative Probability Formula
Cumulative probability answers: "What's the probability I obtain Vex Mythoclast within N weekly clears?" Unlike fixed-rate probability (classic binomial distribution), Vex's graduated bad luck protection requires modified calculations accounting for increasing drop rates each clear.
The complement rule with graduated rates formula:
P(success within N) = 1 - Π[1 - p_i] for i=1 to NWhere p_i = drop rate at clear i. For Vex: p_1 = 0.05, p_2 = 0.10, p_3 = 0.15, ..., p_10+ = 0.50. The product Π[1 - p_i] represents the probability of failing all N attempts with increasing success rates—subtracting from 1 gives cumulative success probability.
This differs fundamentally from fixed-rate cumulative probability P(within N) = 1 - (1 - p)^N because drop rate p changes each trial. Our Destiny 2 Raid Exotic Calculator automates these calculations for any number of clears and current protection stacks.
Worked Example: Vex Mythoclast Probability Within 5 Clears
Let's calculate exact step-by-step probability for obtaining Vex within 5 weekly Vault of Glass clears:
Step 1: Identify Drop Rates for Clears 1-5
- • Clear 1: p_1 = 0.05 (5% base rate)
- • Clear 2: p_2 = 0.10 (5% + 5% protection)
- • Clear 3: p_3 = 0.15 (5% + 10% protection)
- • Clear 4: p_4 = 0.20 (5% + 15% protection)
- • Clear 5: p_5 = 0.25 (5% + 20% protection)
Step 2: Calculate Failure Probability Each Clear
- • P(fail clear 1) = 1 - 0.05 = 0.95
- • P(fail clear 2) = 1 - 0.10 = 0.90
- • P(fail clear 3) = 1 - 0.15 = 0.85
- • P(fail clear 4) = 1 - 0.20 = 0.80
- • P(fail clear 5) = 1 - 0.25 = 0.75
Step 3: Multiply Failure Probabilities (Independent Events)
P(fail all 5) = 0.95 × 0.90 × 0.85 × 0.80 × 0.75
P(fail all 5) = 0.4382 (rounded to 4 decimals)
This represents probability of not getting Vex across all 5 clears with graduated rates
Step 4: Apply Complement Rule for Cumulative Success
P(success within 5) = 1 - P(fail all 5)
P(success within 5) = 1 - 0.4382 = 0.5618 = 56.18%
Interpretation: 56.18% of players obtain Vex within 5 weekly clears
Complete Cumulative Probability Table: All 10 Clears
| Weekly Clear # | Drop Rate | P(This Clear) | Cumulative P(≤N) | Percentile |
|---|---|---|---|---|
| 1 | 5% | 5.00% | 5.00% | 5th |
| 2 | 10% | 9.50% | 14.50% | 14.5th |
| 3 | 15% | 12.83% | 27.33% | 27th |
| 4 | 20% | 14.53% | 41.86% | 42nd |
| 5 | 25% | 14.32% | 56.18% | 56th (Median) |
| 6 | 30% | 13.15% | 69.33% | 69th |
| 7 | 35% | 10.73% | 80.06% | 80th (75th %ile) |
| 8 | 40% | 7.98% | 88.04% | 88th |
| 9 | 45% | 5.38% | 93.42% | 93rd (95th %ile) |
| 10+ | 50% | 3.29% | 96.71% | 97th (Max Cap) |
Interpreting Cumulative Probability for Planning
- ▸Median Planning (50% confidence): Budget 5 weekly clears. Half of all players obtain Vex by this point (56.18% cumulative probability).
- ▸Conservative Planning (75% confidence): Budget 7 weekly clears. Three-quarters of players obtain Vex by this point (80.06% cumulative probability).
- ▸Pessimistic Planning (95% confidence): Budget 10 weekly clears to reach maximum 50% cap (93.42% at clear 9, 96.71% at clear 10). Only 5% of players need more than 9 clears.
- ▸Worst-Case Scenario: Even catastrophically unlucky players reach 50% drop rate by clear 10, then expect ~2 additional clears for success (50% success rate ≈ 2 trials for 75% cumulative).
Raid Exotic Median Clears Analysis
What Are Median Clears and Why Do They Matter?
Median clears represent the 50th percentile—the number of weekly clears by which half of all players have obtained the raid exotic. For Vex Mythoclast, median ≈ 4.7 clears (between clear 4 at 41.86% and clear 5 at 56.18% cumulative probability). This is the single most useful planning metric for setting realistic expectations because it represents typical player experience, not best-case or worst-case scenarios.
Median differs from mean (expected value), which calculates average clears accounting for the full probability distribution including outliers. For Vex with graduated protection capping at 50%, the mean is slightly lower than median due to the accelerating success rates, but median provides more intuitive planning guidance: "If you run Vault of Glass weekly for 5 weeks, you're more likely than not to have Vex Mythoclast."
Percentile-Based Planning: Median vs 75th vs 95th
Median (50th Percentile)
~4.7 clears
56.18% cumulative probability at clear 5
Use for: Realistic expectations, typical player experience
75th Percentile
~6.5 clears
80.06% cumulative probability at clear 7
Use for: Conservative planning, accounting for bad luck
95th Percentile
~9.5 clears
93.42% cumulative probability at clear 9
Use for: Pessimistic planning, high confidence timelines
Common Misconception: Median vs Mean Expected Value
Many players confuse median clears (50th percentile) with mean expected clears. Mean calculates average clears accounting for the full distribution: Σ[i × P(success at clear i)] for i=1 to ∞. For Vex with 50% cap at clear 10+, mean ≈ 4.3 clears. However, median (4.7 clears) is more useful for planning because it represents the typical player experience—half get Vex earlier, half later. Mean is pulled down by lucky players getting Vex on clear 1-2, but median reflects when most players actually obtain the weapon. For farming timeline planning, always use median or higher percentiles, not mean.
Three Character Farming Optimization Strategy
Destiny 2 Three Character Rotation: Maximum Efficiency
Three character rotation is the single most impactful optimization for raid exotic farming in Destiny 2. Since bad luck protection stacks independently per character and each character can loot Atheon once per weekly reset, running Vault of Glass on 3 characters provides 3 separate exotic chances with 3 independent protection stacks per week instead of 1. This doesn't just triple your weekly attempts—it dramatically reduces real-world acquisition time by accelerating protection stack accumulation across your account.
The mathematics: Single character farming has median 4.7 clears = 4.7 weeks real-world time. Three character farming has median 4.7 clears total ÷ 3 characters = ~1.6 weeks real-world time. This 3× speedup applies across all percentiles: 75th percentile drops from 6.5 weeks to 2.2 weeks, 95th percentile drops from 9.5 weeks to 3.2 weeks. For players with limited weekly playtime, three character rotation is non-negotiable for efficient raid exotic acquisition.
How Three Character Bad Luck Protection Works
Each character maintains its own bad luck protection counter that tracks unsuccessful Atheon clears and increments drop rate accordingly. Running Vault of Glass on multiple characters doesn't share or pool protection—each character progresses independently:
Week 1: Initial Clears
- • Character 1: First Atheon clear, 5% chance, doesn't drop → 1 protection stack (10% next week)
- • Character 2: First Atheon clear, 5% chance, doesn't drop → 1 protection stack (10% next week)
- • Character 3: First Atheon clear, 5% chance, doesn't drop → 1 protection stack (10% next week)
- • Result: 3 attempts at 5% each, 3 independent protection stacks acquired
Week 2: Protection Stacks Active
- • Character 1: Second Atheon clear, 10% chance (1 stack), doesn't drop → 2 stacks (15% next week)
- • Character 2: Second Atheon clear, 10% chance (1 stack), doesn't drop → 2 stacks (15% next week)
- • Character 3: Second Atheon clear, 10% chance (1 stack), doesn't drop → 2 stacks (15% next week)
- • Result: 3 attempts at 10% each, protection accelerating across all characters
Week 3: High Protection Rates
- • Character 1: Third clear, 15% chance → DROPS! Vex acquired!
- • Character 2: Third clear, 15% chance → doesn't drop (continue farming if desired)
- • Character 3: Third clear, 15% chance → doesn't drop (continue farming if desired)
- • Result: Vex acquired in week 3 instead of week 5+ with single character
Three Character vs Single Character: Real-World Timeline Comparison
| Planning Scenario | Clears Needed | Single Character | Three Characters | Time Saved |
|---|---|---|---|---|
| Median (50%) | 4.7 clears | 4.7 weeks | 1.6 weeks | 3.1 weeks |
| Conservative (75%) | 6.5 clears | 6.5 weeks | 2.2 weeks | 4.3 weeks |
| Pessimistic (95%) | 9.5 clears | 9.5 weeks | 3.2 weeks | 6.3 weeks |
| Maximum Cap (50% rate) | 10 clears | 10 weeks | 3.3 weeks | 6.7 weeks |
Practical Three Character Setup Requirements
- ▸Character Creation: Can use 3 different classes (Titan/Hunter/Warlock) or 3 same-class characters. Same-class allows armor sharing but faces diminishing pinnacle rewards—choose based on priorities.
- ▸Power Level Requirements: All characters must meet Vault of Glass recommended power (currently 1350+ for normal mode). New characters need campaign completion and power leveling before raid-ready.
- ▸Time Investment Per Week: Vault of Glass takes ~45-60 minutes per clear for experienced fireteams. 3 clears = 2.5-3 hours weekly commitment. Checkpoint saves can reduce time if you split across multiple days.
- ▸Weapon/Armor Transfers: Use Destiny Item Manager (DIM) or similar apps for instant gear transfers between characters. Keep one set of optimized Vault of Glass weapons (Xenophage, Sleeper Simulant, etc.) that all characters can share.
Weekly Raid Lockout Mechanics for Multi-Character Farming
Critical Rules to Maximize Three Character Efficiency
Weekly raid lockout mechanics govern when and how characters can loot encounters. Understanding these rules is critical for avoiding wasted clears that grant no exotic chance or protection stacks:
- 1.One Looted Clear Per Character Per Weekly Reset: After first Atheon loot on Tuesday, that character cannot receive exotic drops or protection stacks until next Tuesday reset, regardless of how many times you kill Atheon.
- 2.Full Raid Completion Required: Holding Atheon checkpoint and killing him does NOT grant exotic chance. Must complete full Vault of Glass from Opening encounter through final boss.
- 3.Cross-Character Checkpoint Sharing: You CAN share checkpoints between characters (e.g., Character 1 reaches Atheon Tuesday, Characters 2 and 3 can join at Atheon Wednesday). However, all characters must still complete full raid from start for exotic eligibility—checkpoint sharing only saves time for non-loot farming activities.
Optimal Weekly Farming Workflow
Tuesday Morning (Reset)
✓ Complete full Vault of Glass on Character 1 (highest protection stacks first for best chance)
✓ Loot Atheon, check for Vex drop
✓ If no drop, protection stack +1 for Character 1
Timing: Complete within 24 hours of reset if possible
Wednesday-Thursday
✓ Complete full Vault of Glass on Character 2
✓ Use Destiny Item Manager to transfer optimized weapons from Character 1
✓ Loot Atheon, acquire second weekly protection stack if no drop
Timing: Mid-week flexibility for scheduling
Friday-Monday
✓ Complete full Vault of Glass on Character 3
✓ Final weekly exotic chance before Tuesday reset
✓ If Vex acquired on any character, stop farming other characters to save time
Timing: Complete before Monday night to avoid reset deadline pressure
Using the Destiny 2 Raid Exotic Drop Rate Calculator
Calculator Features for Vex Mythoclast Planning
Our Destiny 2 Raid Exotic Calculator automates all cumulative probability calculations demonstrated in this guide, providing instant timeline estimates for Vex Mythoclast and other raid exotics. The calculator accounts for:
- •Current Bad Luck Protection Stacks: Input your current protection stacks per character to calculate remaining clears needed for median/percentile probabilities.
- •Three Character Optimization: Toggle 1/2/3 character mode to compare real-world timeline differences and optimize farming strategy.
- •Graduated Rate Progressions: Supports all raid exotic bad luck protection systems (5% + 5%, 10% + 3.3%, 10% + 5% curves) for accurate cumulative probability.
- •Percentile Planning: Shows median, 75th percentile, 95th percentile clears needed for confidence-based timeline planning.
Step-by-Step Calculator Usage
Step 1: Select Raid Exotic
Choose Vex Mythoclast from dropdown. Calculator automatically loads 5% base + 5% per clear protection curve.
Step 2: Input Current Protection Stacks
Enter your current unsuccessful clears (0-9 stacks). If first attempt, enter 0. If 3 unsuccessful clears, enter 3 for 20% current rate.
Step 3: Set Character Count
Toggle 1/2/3 character mode. Calculator adjusts real-world weeks accordingly (3 characters = 3× weekly stacks).
Step 4: Review Results
Calculator displays: current drop rate, cumulative probability for next N clears, median/75th/95th percentile timelines, and real-world weeks estimate.
Practical Calculator Use Cases
- ▸First-Time Farmer: Planning initial Vex grind. Set 0 protection stacks, 3 characters → calculator shows 1.6 weeks median, 3.2 weeks pessimistic (95%).
- ▸Mid-Grind Check-In: Already completed 5 clears without drop (5 protection stacks, 30% current rate). Calculator shows remaining clears needed for high confidence acquisition.
- ▸Single vs Multi-Character Comparison: Toggle between 1/2/3 character modes to visualize time savings from multi-character farming (often 3-4× speedup).
- ▸Cross-Exotic Planning: Compare Vex (median 4.7 clears) vs Eyes of Tomorrow (median ~4-5 clears but 100% at 20) vs 1000 Voices (median ~3-4 clears) for priority targeting.
Understanding the Methodology Behind LootCalc
Data Sources and Validation
All Vex Mythoclast drop rate calculations and bad luck protection progressions are validated against:
- •Bungie API Data: Official Destiny 2 API provides raid completion tracking and exotic acquisition timestamps for statistical analysis across player population.
- •Community Crowdsourced Submissions: Over 5,000 player-submitted Vault of Glass completion logs with Vex acquisition clear counts validate median/percentile estimates.
- •Reddit r/DestinyTheGame Analysis: Community data collection threads tracking bad luck protection progressions confirm 5% base + 5% increase curve.
- •Bungie TWABs (This Week at Bungie): Official patch notes and developer commentary confirming bad luck protection mechanics and rate adjustments.
For complete transparency on our mathematical methods, data validation processes, and statistical approaches, see our LootCalc Methodology & Data Sources page. All formulas presented in this guide are reproducible using standard probability theory and match community-validated rates.
Frequently Asked Questions
Frequently Asked Questions
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