Editing Halfling Luck

{{Passive feature page
| image = Halfling Luck.webp
| icon = Halfling Luck Icon.webp
| summary = '''Halfling Luck''' is a passive feature in Baldur's Gate 3 that grants all halflings to reroll a die when it lands on a 1 for an Attack Roll, Ability Check, or Saving Throw.
| description = When you roll a 1 for an {{Attack Roll}}, {{Ability Check}}, or {{Saving Throw}}, you can reroll the die and must use the new roll.
| race learns at level 1 = Halfling
| notes =
* It is possible for the new roll to be another 1.
* As of patch 6, when rolling with advantage, the following rules apply:
** If one die rolls a 1, it's re-rolled, and the higher of the two dice used.
** If both dice roll a 1, they are '''both''' re-rolled, and the higher one used.
* The chance to hit displayed when hovering an attack on an enemy doesn't take into account Halfling Luck.
* Halfling Luck is particularly useful to avoid failures for ability checks and saving throws when the roll would only fail on a critical miss.
** On a normal roll that succeeds on a 2 or more, Halfling Luck would reduce the chance to fail from 1/20 to 1/400.
** On a roll with advantage that succeeds on a 2 or more, Halfling Luck would reduce the chance to fail from 1/400 to 1/160000, making it practically impossible to fail. With [[Karmic Dice]] active, it may be simply impossible to roll 4 critical failures in a row.
** Traders can get all their easy to steal item stolen without fear of missing a single roll.
*** Be mindful that it can make your character {{SAI|Heavily Encumbered (Condition)|Heavily Encumbered}} which gives disadvantage on all ability checks, including further pickpocket attempts.
** Also useful to avoid [[Concentration]] getting interrupted too often by constitution save critical misses when taking low damage.
}}

==Math==
=== Chances of succeeding a specific roll===
See [[Advantage#Math|Advantage math section]] for comparison.
{| class="wikitable"
|+Chance of rolling a target number or above on 1d20 with Halfling Luck
|-
! Target on 1d20 !! Luck Normal Roll !! Luck with Advantage !! Luck with Disadvantage
|-
|1||100%||100%||100%
|-
|2||99.75%||99.9994%||99.5%
|-
|3||94.50%||99.7%||89.3%
|-
|4||89.25%||98.84%||79.66%
|-
|5||84%||97.44%||70.56%
|-
|6||78.75%||95.48%||62.02%
|-
|7||73.5%||92.98%||54.02%
|-
|8||68.25%||89.92%||46.58%
|-
|9||63%||86.31%||39.69%
|-
|10||57.75%||82.15%||33.35%
|-
|11||52.5%||77.44%||27.56%
|-
|12||47.25%||72.17%||22.33%
|-
|13||42%||66.36%||17.64%
|-
|14||36.75%||59.99%||13.51%
|-
|15||31.5%||53.08%||9.92%
|-
|16||26.25%||45.61%||6.89%
|-
|17||21%||37.59%||4.41%
|-
|18||15.75%||29.02%||2.48%
|-
|19||10.5%||19.9%||1.1%
|-
|20||5.25%||10.22%||0.28%
|}

=== Chance to hit comparisons ===
On a normal roll, Halfling Luck multiplies the chance to hit by :
* 1.05 whatever the target roll is
** This would be the most noticeable for a target roll of 2 which would add a flat 4.75% chance to hit or almost +1 on a d20.
** For a target roll of 20 it would add a flat 0.25% chance to hit, which would be a critical success.

On a roll with Advantage, Halfling Luck multiplies the chance to hit by :
* 1.003 for a target roll of 2 or a flat +0.25% chance to hit
* 1.01 for a target roll of 3 or a flat +0.70% chance to hit
...
* 1.03 for a target roll of 11 or a flat +2.44% chance to hit
...
* 1.05 for a target roll of 20 or a flat +0.47% chance to hit, which would be a critical success.

On a roll with Disadvantage, Halfling Luck multiplies the chance to hit by :
* 1.10 whatever the target roll is
** This would be the most noticeable for a target roll of 2 which would add a flat 9.25% chance to hit or almost +2 on a d20.
** For a target roll of 20 it would add a flat 0.03% chance to hit, which would be a critical success.

=== Chance to fail comparisons ===
On a normal roll, Halfling Luck divides the chance to fail by :
* 20 for a target roll of 2
* 1.82 for a target roll of 3
* 1.40 for a target roll of 4
...
* 1.003 for a target roll of 20

On a roll with Advantage, Halfling Luck divides the chance to fail by : 
* 400 for a target roll of 2
* 3.31 for a target roll of 3
* 1.95 for a target roll of 4
...
* 1.01 for a target roll of 20

On a roll with Disadvantage, Halfling Luck divides the chance to fail by : 
* 19.52 for a target roll of 2
* 1.78 for a target roll of 3
* 1.36 for a target roll of 4
...
* 1.0003 for a target roll of 20

==External Links==
*[https://docs.google.com/spreadsheets/d/1ebI3SACmQFpC82tSN5UOQEI4HwizHDOPZDofTJqh9Hs Advantage and Halfling luck calculation] by Kalaeman