Wurm action simulator

Find the setup that gives your skill room to grow.

A reorganized, plain-language presentation of Dreamsleeve’s 14 Wurm action models, designed to make the original inputs and results easier to understand.

Step 1

Choose an action

Skill-gain rolls

Estimate mining action power after the pickaxe skill and quality checks are included.

For grinding, compare veins and pickaxes by the share of rolls that land from 0 to 40.

Step 2

Enter your setup

Your setup

Step 3

Your result will appear here.

Check the values on the left, then run the simulation. You will get a summary, an interpretation, and a readable distribution.

  • 0–40 useful skill-gain power
  • 0+ successful action
  • P10–P90 the middle 80% of results

How to use the grinder

Change one thing, compare the useful result.

The tool is most useful as a comparison between two possible setups, not as a promise about one action.
  1. 01
    Pick the exact activity

    Choose whether you care about a skill-check roll, the quality produced, or the number of improve actions.

  2. 02
    Copy values from the game

    Enter your real skill, tool quality, sub-skills, material, and target. Hover-free explanations sit beneath every field.

  3. 03
    Read the result that matters

    For skill grinding, use Useful skill-gain rolls—not average power or success rate alone. For quality, use the middle 80% range. For smithing, use median actions.

  4. 04
    Change one variable and compare

    Try a different tool quality, crop, vein, slope, or target QL. Keep the setup that puts more actions in the useful range without changing everything at once.

Why the power range matters

A successful action is not automatically a useful grinding action.

For the skill-check activities modeled here, the grinder treats power from 0 through 40 as the useful skill-gain window. Your goal is to place as many of all actions in that middle band as possible.

−100 to −1Failed checkThe action fails and is outside the useful skill-gain window.
0 to 40Useful for grindingThe check succeeds while remaining difficult enough to qualify.
41 to 100Successful, but too easyThe action succeeds above the model’s skill-gain power window.

What to optimize: choose the setup with the highest Useful skill-gain rolls percentage. A 99% success rate can be worse for grinding if most of those successes land above 40 power. Likewise, making the action extremely difficult wastes rolls below 0.

Landing from 0–40 makes a roll eligible in this model; it does not guarantee a visible skill tick. Skill-specific gain chance, action duration, sleep bonus, nutrition, enchantments, and server rules can still affect actual gains.

Do not optimize average power

A higher average power usually means easier actions, but easy rolls can move above 40 and stop helping the grind. Optimize the useful-roll percentage instead.

Middle 80% range

P10 to P90 removes the most extreme ten percent at each end. It is usually more useful than the full minimum-to-maximum range when planning quality or workload.

Simulation, not a guarantee

Wurm uses random rolls and may include circumstances beyond the selected model. Use these figures to compare setups; actual actions will still vary.

Under the hood

How the simulation reaches its answer.

This page does not introduce or claim a separate calculation model. It implements and reorganizes the logic from Dreamsleeve’s Grinder: layered Wurm checks are repeated thousands of times and the resulting distribution is summarized in a more explanatory layout.

01Resolve supporting checksTool, parent, and secondary skills create model-specific bonuses.
02Build effective skillSkill, tool quality, and applicable bonus are combined.
03Roll against difficultyA bounded, bell-shaped power roll is produced from −100 to 100.
04Repeat and classifyEvery roll is placed into the relevant power, quality, or action-count range.

The model first converts the displayed skill into an effective skill. Without an applicable tool, a positive bonus moves the skill toward a higher ceiling; the bonus used for this step is capped at 70.

Without a toolceiling = (100 + skill) ÷ 2change = min(skill, ceiling − skill) × min(bonus, 70) ÷ 100effective skill = skill + change

When tool quality applies, quality modifies the skill before a positive bonus is added. A tool below your skill pulls effective skill down; a tool above it raises effective skill, but with diminishing effect as values approach 100.

With a toolif QL < skill: base = (skill + QL) ÷ 2if QL ≥ skill: base = skill + skill × (QL − skill) ÷ 100

Effective skill S and action difficulty D determine the centre and width of a bell-shaped distribution. The cubic term makes large skill–difficulty gaps matter more than a simple subtraction would.

Reference roll parameterscentre shift = (S³ − D³) ÷ 50,000 + (S − D)base width = 30 − |S − D| ÷ 4

The simulator then draws a normally distributed result, applies the reference rejection behaviour, and keeps the final power between −100 and 100. This process is repeated for the selected simulation count. “Nearest” or “round down” is applied to each result before it is counted in the graph.

Why your in-game result can differ: each individual Wurm action is random, and the reference model may not include every current skill-specific rule, enchantment, server modifier, or later game update. The simulator is strongest when comparing two setups under the same assumptions.