Dr. Ratio
Last updated 2026-08-27
This article is about the playable character. For the Dreamscape Pass Sticker, see Dr. Ratio (Dreamscape Pass Sticker).
"The most annoying thing about idiocy is that you can't explain it to an idiot."[3]
Dr. Veritas Ratio is a playable character in Honkai: Star Rail.
A candid and self-centered Intelligentsia Guild member, who often conceals his appearance with a strange plaster sculpture.
He demonstrated unparalleled intelligence and talent since his youth, but now refers to himself as a "Mundanite." He firmly believes that intellect and creativity are not confined to geniuses. He seeks to distribute knowledge to the entire universe to cure the persistent disease named ignorance.[3]
Combat Info
Ascensions and Stats
| Ascension Phase | Level | Base HP | Base ATK | Base DEF | Base SPD | Ascension Costs |
|---|---|---|---|---|---|---|
| 0✦ | 1/20 | 142 | 105 | 62 | 103 | (0 → 1) |
| 20/20 | 277 | 205 | 122 | 103 | ||
| Ascension Cost (0 → 1) | ||||||
| 1✦ | 20/30 | 335 | 248 | 147 | 103 | (1 → 2) |
| 30/30 | 406 | 300 | 178 | 103 | ||
| Ascension Cost (1 → 2) | ||||||
| 2✦ | 30/40 | 463 | 343 | 203 | 103 | (2 → 3) |
| 40/40 | 534 | 396 | 235 | 103 | ||
| Ascension Cost (2 → 3) | ||||||
| 3✦ | 40/50 | 591 | 438 | 260 | 103 | (3 → 4) |
| 50/50 | 662 | 491 | 291 | 103 | ||
| Ascension Cost (3 → 4) | ||||||
| 4✦ | 50/60 | 719 | 533 | 316 | 103 | (4 → 5) |
| 60/60 | 791 | 586 | 347 | 103 | ||
| Ascension Cost (4 → 5) | ||||||
| 5✦ | 60/70 | 848 | 628 | 373 | 103 | (5 → 6) |
| 70/70 | 919 | 681 | 404 | 103 | ||
| Ascension Cost (5 → 6) | ||||||
| 6✦ | 70/80 | 976 | 723 | 429 | 103 | — |
| 80/80 | 1,047 | 776 | 460 | 103 | ||
308,000 CreditAbilities
| Icon | Type | Name | Tag | Energy | Toughness Reduction | ||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 | Basic ATK | Mind is Might | Single Target | Generation: 20 | 10 | ||||||||||||||||||||||||||||||||
 | Skill | Intellectual Midwifery | Single Target | Generation: 30 | 20 | ||||||||||||||||||||||||||||||||
Deals Imaginary DMG equal to 75%—165% of Dr. Ratio's ATK to a single target enemy.
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 | Ultimate | Syllogistic Paradox | Single Target | Cost: 140 Generation: 5 | 30 | ||||||||||||||||||||||||||||||||
Deals Imaginary DMG equal to 144%—259.2% of Dr. Ratio's ATK to a single target enemy and applies Wiseman's Folly. When Dr. Ratio's teammates attack a target afflicted with Wiseman's Folly, Dr. Ratio launches 1 instance of his Talent's Follow-up ATK against this target.
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 | Talent | Cogito, Ergo Sum | Single Target | Generation: 5 | 10 | ||||||||||||||||||||||||||||||||
When using his Skill, Dr. Ratio has a 40% fixed chance of launching a Follow-up ATK against his target for 1 time, dealing Imaginary DMG equal to 135%—297% of Dr. Ratio's ATK. For each debuff the target enemy has, the fixed chance of launching Follow-up ATK increases by 20%. If the target enemy is defeated before the Follow-up ATK triggers, the Follow-up ATK will be directed at a single random enemy instead.
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 | Technique | Mold of Idolatry | Impair | ||||||||||||||||||||||||||||||||||
After using Technique, creates a Special Dimension that Taunts nearby enemies, lasting for 10 second(s). After entering battle with enemies in this Special Dimension, there is a 100% base chance to reduce each single enemy target's SPD by 15% for 2 turn(s). Only 1 Dimension Effect created by allies can exist at the same time.
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Traces
| Trace Level | Required Ascension | Credits [Subtotal] | Character Ascension Materials and Trace Materials [Subtotal] | Trace Materials [Subtotal] |
|---|---|---|---|---|
| 1 → 2 | 2✦ | 5,000 [5,000] |  6 [6] |  3 [3] |
| 2 → 3 | 3✦ | 10,000 [15,000] |  3 [3] |  3 [3] |
| 3 → 4 | 4✦ | 20,000 [35,000] | 4 [7] | 5 [8] |
| 4 → 5 | 5✦ | 45,000 [80,000] |  3 [3] |  3 [3] |
| 5 → 6 | 6✦ | 160,000 [240,000] | 4 [7] | 8 [11] |
Total Cost (1 → 6 for Basic ATK Trace)
240,000 Credit
240,000 Credit| Trace Level | Required Ascension | Credits [Subtotal] | Character Ascension Materials and Trace Materials [Subtotal] | Trace Materials [Subtotal] | ||
|---|---|---|---|---|---|---|
| 1 → 2 | 1✦ | 2,500 [2,500] | 3 [3] | |||
| 2 → 3 | 2✦ | 5,000 [7,500] | 6 [9] | 3 [3] | ||
| 3 → 4 | 3✦ | 10,000 [17,500] | 3 [3] | 3 [3] | ||
| 4 → 5 | 4✦ | 20,000 [37,500] | 4 [7] | 5 [8] | ||
| 5 → 6 | 30,000 [67,500] | 6 [13] | 7 [15] | |||
| 6 → 7 | 5✦ | 45,000 [112,500] | 3 [3] | 3 [3] | ||
| 7 → 8 | 80,000 [192,500] | 4 [7] | 5 [8] |  1 [1] | ||
| 8 → 9 | 6✦ | 160,000 [352,500] | 8 [16] | 1 [2] |  1 [1] | |
| 9 → 10 | 300,000 [652,500] | 14 [30] | 1 [3] | 1 [2] | ||
Total Cost (1 → 10 for one Trace)
652,500 Credit
652,500 Credit ATK BoostATK increases by 4.0% | ||
 SummationWhen Dr. Ratio uses his Skill, for every debuff on the target, his CRIT Rate increases by 2.5% and CRIT DMG by 5%. This effect can stack up to 6 time(s). Req. Character Ascension 2 |
 CRIT Rate BoostCRIT Rate increases by 2.7% Req. Character Ascension 2 |
ATK Boost ATK increases by 4.0% Req. Character Ascension 3 |
 DEF BoostDEF increases by 5.0% Req. Character Ascension 3 | ||
 InferenceWhen Skill is used to attack an enemy target, there is a 100% base chance to reduce the attacked enemy target's Effect RES by 10% for 2 turn(s). Req. Character Ascension 4 |
ATK Boost ATK increases by 6.0% Req. Character Ascension 4 |
CRIT Rate Boost CRIT Rate increases by 4.0% Req. Character Ascension 5 |
| ATK Boost ATK increases by 6.0% Req. Character Ascension 5 | ||
 DeductionWhen dealing DMG to a target that has 3 or more debuff(s), for each debuff the target has, the DMG dealt by Dr. Ratio to this target increases by 10%, up to a maximum increase of 50%. Req. Character Ascension 6 |
DEF Boost DEF increases by 7.5% Req. Character Ascension 6 |
CRIT Rate Boost CRIT Rate increases by 5.3% Req. Character Lv. 75 |
| ATK Boost ATK increases by 8.0% Req. Character Lv. 80 | ||
Eidolons
| Icon | Name | Level |
|---|---|---|
 | Pride Comes Before a Fall | 1 |
| The maximum stackable count for the Trace "Summation" increases by 4. When a battle begins, immediately obtains 4 stacks of Summation. Needs to unlock Summation first. | ||
 | The Divine Is in the Details | 2 |
| When his Talent's Follow-up ATK hits a target, for every debuff the target has, deals Imaginary Additional DMG equal to 20% of Dr. Ratio's ATK. This effect can be triggered for a maximum of 4 time(s) during each Follow-up ATK. | ||
 | Know Thyself | 3 |
| Ultimate Lv. +2, up to a maximum of Lv. 15. Basic ATK Lv. +1, up to a maximum of Lv. 10. | ||
 | Ignorance Is Blight | 4 |
| When triggering the Talent, additionally regenerates 15 Energy for Dr. Ratio. | ||
 | Sic Itur Ad Astra | 5 |
| Skill Lv. +2, up to a maximum of Lv. 15. Talent Lv. +2, up to a maximum of Lv. 15. | ||
 | Vincit Omnia Veritas | 6 |
| Additionally increases the trigger count for "Wiseman's Folly" by 1. The DMG dealt by the Talent's Follow-up ATK increases by 50%. | ||
Achievements
There are 4 Achievements related to Dr. Ratio:
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Name | Category | Description | Hidden | Version | 
|
|---|---|---|---|---|---|---|
|
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Truth Must Circulate Like Currency | Moment of Joy | Take part in 1 match(es) in Support Assist using Dr. Ratio | Yes | 2.0 | 5 |
|
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Trigger Warning | Eager for Battle | Use Dr. Ratio's Technique, Mold of Idolatry, to Taunt 6 or more enemies at once | Yes | 1.6 | 5 |
|
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Chain Peoplebreaker | Eager for Battle | In a single battle, trigger the follow-up attack effect from Dr. Ratio's Talent, Cogito Ergo Sum, for 4 consecutive turns | No | 1.6 | 5 |
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Planet of Festivities Special Team | Eager for Battle | Win 1 battle(s) with a team comprising Topaz & Numby, Dr. Ratio, Aventurine, and Jade | Yes | 2.3 | 5 |
Availability
Expired
- Proposal from Dr. Ratio available between the start of the Version 1.6 "Panta Rhei" Event Warp and the end of Version 2.1[4]
Event Warps
Dr. Ratio has been promoted or featured with a drop-rate boost in 2 Event Warps:
| Warp | Featured | Duration | Version |
|---|---|---|---|
 Panta Rhei 2024-01-17 |
  Dr. Ratio |
January 17, 2024 – February 5, 2024 | 1.6 |
 Panta Rhei 2025-04-30 |
Dr. Ratio |
April 30, 2025 – May 20, 2025 | 3.2 |
Other Languages
Dr. Ratio
| Language | Official Name |
|---|---|
| English | Dr. Ratio |
| Chinese (Simplified) | 真理医生 |
| Chinese (Traditional) | 真理醫生 |
| Japanese | Dr.レイシオ |
| Korean | Dr. 레이시오 |
| Spanish | Dr. Ratio |
| French | Dr Ratio |
| Russian | Доктор Рацио |
| Thai | Dr. Ratio |
| Vietnamese | Dr. Ratio |
| German | Dr. Wahrheit |
| Indonesian | Dr. Ratio |
| Portuguese | Dr. Ratio |
Veritas Ratio
| Language | Official Name |
|---|---|
| English | Veritas Ratio |
| Chinese (Simplified) | 维里塔斯•拉帝奥 |
| Chinese (Traditional) | 維里塔斯•拉帝奧 |
| Japanese | ベリタス・レイシオ |
| Korean | 베리타스•레이시오 |
| Spanish | Veritas Ratio |
| French | Veritas Ratio |
| Russian | Веритас Рацио |
| Thai | Veritas Ratio |
| Vietnamese | Veritas Ratio |
| German | Veritas Ratio |
| Indonesian | Veritas Ratio |
| Portuguese | Veritas Ratio |
Change History
Introduced in Version 1.4 • Released in Version 1.6
- Updates to character voice-overs:
- New voice-over for All Languages:
- "About Aventurine • Waveflair"
- "Added to Team With Aventurine • Waveflair"
- New voice-over for All Languages:
- Updates to character voice-overs:
- New voice-over for All Languages:
- "About Sunday"
- "Added to Team With Sunday"
- New voice-over for All Languages:
- Updates to character voice-overs:
- New voice-over for All Languages:
- "About Aventurine"
- "Added to Team With Aventurine"
- New voice-over for All Languages:
- Dr. Ratio was released as a playable character.
- Dr. Ratio was introduced.
References
- ↑ Trailblaze Mission, In Our Time: Everything that Rises Must Converge
Black Swan: Yes, or how else can we explain it? The Family deliberately used the Watchmaker's invitation to keep all the Pathstriders here but banished the Emanator of the Nihility... - ↑ 2.0 2.1 2.2 2.3 Chinese Character Reveal, Honkai: Star Rail Bilibili. Retrieved October 31, 2023.
- ↑ 3.0 3.1 Character Reveal, Honkai: Star Rail Twitter. Retrieved October 31, 2023.
- ↑ Proposal from Dr. Ratio, Honkai: Star Rail Twitter. Retrieved December 15, 2023.
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