Weight
Weight
Weight is the universal mechanic that governs how much a character can carry and how heavy individual items are. The unit of weight is the stone, displayed everywhere weight matters: item tooltips, container contents summary, paperdoll status. Weight is a load-bearing constraint in nearly every UO scenario — crafters can only haul a fixed load of raw material before being immobilized; champion-spawn participants can only loot a finite quantity of gold/items before bagsplitting; archers must reckon with the weight of arrows, kegs, and quivers. Weight interacts directly with Strength (which determines max carry capacity), with item modifiers like Lower Reagent Cost and Lower Ammo Cost (which reduce per-cast/per-shot weight load), and with the Weight Reduction property on certain quivers (Mondain's_Legacy) that reduces the carried-weight contribution of contained items.
The stone — UO's weight unit
The stone is the canonical unit of weight in Ultima Online. Item weights are integer values in stones; container totals and carry-capacity displays are likewise denominated in stones. Some implementation quirks:
| Quirk | Detail |
|---|---|
| Some items have no weight | Spellbooks, certain quest items, and bookkeeping objects |
| Some items have fixed weight regardless of contents | Bulk Order Books always weigh 1 stone regardless of how many BODs they hold |
| Like items can have different weights | Rubble and Blackrock vary by source spawn — collectors notice this on display rooms |
| Weight math doesn't always add up | A full keg weighs 100 stones and contains 100 potions at 1 stone each, but an empty keg weighs 20 stones — there's a 20-stone "container overhead" that vanishes when liquid is added |
These edge cases are well-known among long-time players and are worth checking in any weight-critical loadout.
Base character weight
| Mechanic | Value |
|---|---|
| Base character weight | 14 stones (race and sex independent) |
| Occasional bug | At times, the base reads as 13 stones — a long-standing minor inconsistency |
| Worn equipment | Adds to the carried weight even when equipped (not in pack) |
The 14-stone baseline means a fresh character with empty pack already "owes" 14 stones to their carry capacity calculation.
Weight Reductions
Three mechanisms reduce per-action weight burden:
| Mechanism | Effect | Affected gameplay |
|---|---|---|
| Lower Reagent Cost (LRC) | Reduces the number of reagents consumed per spell cast — the reagents pulled from the character's pouch are physically fewer | Mages and Necromancers carry less reagent weight |
| Lower Ammo Cost (LAC) | Reduces the number of arrows/bolts consumed per archery shot | Archers can hunt longer between resupply |
| Weight Reduction (Quiver property) | The quiver counts a percentage less of its contents toward total carried weight (e.g. Quiver of the Elements has 50% Weight Reduction) — physical contents stay the same but the carry-burden math is reduced | Archer / Throwing builds can carry far more arrows |
The Quiver of the Elements is the canonical reference — its 50% Weight Reduction effectively doubles the practical ammo capacity an archer can field-carry.
Containers and carry capacity
A character's load is split between the main backpack and any equipped or held containers (pouches, bags, secondary backpacks):
| Container category | Capacity |
|---|---|
| All containers (general rule) | Weight limit 400 stones |
| Locked-down containers | Can exceed 400 stones |
| Pre-Pub37 locked-down container overflow | Containers used to overflow at 65,535 stones before the bug was fixed by Publish 37 |
| Main character backpack | Hard-capped at 550 stones total |
Carrying capacity formula
Maximum carrying capacity is derived from Strength:
| Race | At 125 STR carrying capacity |
|---|---|
| Gargoyle | 477 stones |
| Elf | 477 stones |
| Human | 477 + 60 (Strong Back racial) = 537 stones |
The per-STR contribution is 3.5 stones per point of STR. The base value (without STR contribution) is the residual, plus the Human +60 racial bonus. Strength Bonus modifiers (e.g. +5 STR rings, +8 STR Bonus chestpieces) also count toward the carrying-capacity calculation — a character with 125 base STR + 25 STR Bonus = 150 effective STR for carry math.
The maximum useful carrying capacity is around 600 stones:
| Component | Cap |
|---|---|
| Carry capacity (STR-derived) | ~600 stones (Human max-STR-bonused) |
| Main backpack | 550 stones |
| Practical limit | The lower of the two, plus equipped-container content |
A character can technically have a STR-derived capacity above 550 (with Strong Back + STR Bonus stacking), but the backpack is the hard ceiling for unsorted contents. Wearing/holding heavy gear beyond 550 in the backpack still adds to carry-capacity utilization but doesn't fit in the pack.
Carry weight effects on movement
When carry weight exceeds capacity:
| State | Effect |
|---|---|
| Below capacity | No movement penalty |
| Over capacity | Stamina drains continuously while moving; movement may slow |
| Significantly over | Cannot move (over-capacity by a large margin pins the character) |
The Stamina-drain mechanic is why heavy carriers (loot-laden champion-spawn participants, miner-haulers) often need rest stops to recover Stamina.
Notable weight oddities
| Item | Notable weight |
|---|---|
| Empty keg | 20 stones |
| Full keg | 100 stones (contains 100 potions, each 1 stone — math inconsistency, see above) |
| Spellbook | 0 stones (since Publish 21, November 25, 2003 — earlier displayed both weight and item count) |
| Reagent pouch (full) | ~5 stones depending on count |
| Bulk Order Book | 1 stone regardless of BOD count |
| Plant treated from a Potion Keg | A bug (per a December 2007 Stratics Post): when treated directly from a keg, the keg's weight does not change — it remains 100 stones until 1 potion is left, or until you fill an Empty Bottle from the keg and then replace it. Workaround: extract a potion and re-keg it to force the weight recount |
Practical guidance
| Build | Weight management priority |
|---|---|
| Pure Mage | LRC suit (40% cap) drops reagent burden to negligible — focus on jewelry/clothing weight |
| Archer | Quiver with Weight Reduction (50% recommended) is the canonical per-shot weight saver |
| Smith / Miner | High STR + strong-back race (Human) maximizes load; multiple secured houses with mining nodes near home minimize haul cycles |
| Champion-spawn looter | Bring multiple containers; loot-bags on all beneficial pets; gold weight (1 stone per 50 gp) is the limiting factor for late-stage loot |
| PvP | Run light — only essentials (potions, bandages, runebook); high movement speed preserves combat positioning |
Stones — the unit nomenclature
The stone unit appears in many contexts:
| Context | Usage |
|---|---|
| Weight tooltip | "Weight: 5 stones" |
| Carry capacity | "Capacity: 537 stones" |
| Container content total | "Stones: 287/400" |
| Gold-weight-as-stones | 50 gp = 1 stone |
The unit is metaphorical — stones are not literal rocks, but a measurement unit borrowed from Imperial weight tradition (1 stone = 14 lbs in real-world Imperial; UO uses the unit purely abstractly).
See also
- Strength (statistic) — drives carry capacity (3.5 stones per STR)
- Statistics — STR/DEX/INT overview
- Reagent — the items reduced by Lower Reagent Cost
- Mondain's Legacy — the expansion that introduced Weight Reduction quivers
- Publish 21 — Spellbook weight removed (November 2003)
- Publish 37 — Locked-down container overflow bug fixed
- Item Properties — full item-property reference (LRC, LAC, Weight Reduction)