Calculator Methodology

The Point Buy Cost Table

The core of the calculator implements the official cost table from the 2014 Player's Handbook (Chapter 1, page 13). Each ability score costs a specific number of points from your 27-point budget:

Note that the cost jumps by 2 between scores 13 and 14, and again between 14 and 15. This is intentional in the official rules — higher scores cost disproportionately more to reflect their greater mechanical impact.

Starting Score and Minimum/Maximum

Every ability score starts at 8 (costing 0 points). You cannot reduce a score below 8 through point buy, and you cannot raise a score above 15 before racial bonuses. These constraints are hardcoded from the PHB. After racial bonuses are applied, scores can reach 17 (from 15 base + 2 racial) at character creation.

The calculator enforces these constraints in real time: attempting to reduce a score below 8 or raise it above 15 has no effect. The custom point buy tool allows adjusting these limits for homebrew variant rules.

Racial Bonus System

Racial bonuses are implemented as fixed additions applied after point buy allocation, reflecting the 2014 PHB racial ASI rules. Each race entry in our database is sourced from the relevant official publication. We maintain a mapping from race name to ASI values that's updated when sourcebooks are revised through official errata.

For races with variable bonuses (Variant Human, Half-Elf's +1/+1 portion, Custom Lineage), the calculator presents selection interfaces that enforce the appropriate constraints — for example, ensuring Variant Human's two +1 bonuses go to different ability scores, and that Custom Lineage's +2 goes to exactly one score.

The 2024 PHB mode replaces fixed racial ASIs with a flexible +2/+1 allocation drawn from the character's background. In 2024 mode, the calculator allows free placement of these bonuses after the point buy phase.

Modifier Calculation

Ability score modifiers are calculated using the standard 5e formula: modifier = floor((score − 10) / 2). This is implemented as integer floor division. For example: score 15 → (15−10)/2 = 2.5 → floor = 2 (+2 modifier). Score 8 → (8−10)/2 = −1 → floor = −1 (−1 modifier).

This formula is consistent with the 2014 PHB ability score modifier table and is unchanged in the 2024 PHB.

Build Saving and Comparison

Build data is stored in browser localStorage under the key 5e-point-buy-builds. No data is transmitted to external servers. Builds are stored as JSON objects containing the ability score array, selected race and class, rule set version, and a timestamp. The calculator loads and validates stored builds on startup, discarding any that fail schema validation.

The multi-compare feature loads up to 4 builds simultaneously, rendering them side-by-side for visual comparison. Comparisons highlight statistically significant differences (scores that differ by 2+ points) to aid build analysis.

Rules Version Handling

The calculator maintains separate rule sets for 2014 PHB and 2024 PHB. Switching between them reloads racial bonus data (fixed ASIs for 2014, flexible background-based ASIs for 2024) and adjusts UI constraints accordingly. The user's selected rule set is persisted in localStorage and restored on page load.

When content pages reference rules that differ between 2014 and 2024 (particularly racial ASIs), both versions are explicitly noted with clear labels. We don't assume one rule set over the other without specifying which.

Corrections and Updates

When WotC publishes errata that changes point buy rules, racial ASIs, or other implemented mechanics, we update the calculator within 30 days. We verify the update against both the errata document and the updated PHB text before deploying. All rule changes affecting calculator behavior are logged in the changelog.