diff --git a/.forgejo/workflows/test.yaml b/.forgejo/workflows/test.yaml
index 33df8d8..7c48ad6 100644
--- a/.forgejo/workflows/test.yaml
+++ b/.forgejo/workflows/test.yaml
@@ -19,3 +19,4 @@ jobs:
       - run: npm ci
       - run: npm run build --if-present
       - run: npm test
+      - run: npm run lint
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index c41d085..8d6b548 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -19,3 +19,4 @@ jobs:
       - run: npm ci
       - run: npm run build --if-present
       - run: npm test
+      - run: npm run lint
diff --git a/.vscode/settings.json b/.vscode/settings.json
index d46602a..65fe597 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -1,7 +1,7 @@
 {
     "vitest.commandLine": "npx vitest",
     "editor.codeActionsOnSave": {
-        "source.fixAll.eslint": true
+        "source.fixAll.eslint": "explicit"
     },
     "editor.defaultFormatter": "esbenp.prettier-vscode",
     "git.ignoreLimitWarning": true,
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000..818ba84
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,31 @@
+# Contributing to Profectus
+
+Thank you for considering contributing to Profectus! We appreciate your interest in improving our project. Please take a moment to review the following guidelines to streamline the contribution process.
+
+## Getting Started
+
+For detailed instructions on setting up local development environment, please refer to the [Setup Guide](https://moddingtree.com/guide/getting-started/setup).
+
+## Contributing
+
+Make sure to open your PR on Incremental Social - the GitHub repo is just a mirror!
+
+### Code Review
+
+All PRs must be reviewed and approved by at least one of the project maintainers before merging. Please be patient during the review process and be open to feedback.
+
+### Testing
+
+Ensure that your changes pass all existing tests and, if applicable, add new tests to cover the changes you've made. Run `npm run test` to run all the tests.
+
+## Code Style
+
+We use ESLint and Prettier to enforce consistent code style throughout the project. Before submitting a PR, run `npm run lint:fix` to automatically fix any linting issues.
+
+## Issue Reporting
+
+If you encounter a bug or have a suggestion for improvement, please open an issue on Incremental Social. Provide as much detail as possible, including an example repo or steps to reproduce the issue if applicable.
+
+## License
+
+By contributing to Profectus, you agree that your contributions will be licensed under the project's [LICENSE](./LICENSE).
diff --git a/package.json b/package.json
index 3c1c415..f0ce56b 100644
--- a/package.json
+++ b/package.json
@@ -9,7 +9,9 @@
     "preview": "vite preview",
     "test": "vitest run",
     "testw": "vitest",
-    "serve": "vite preview --host"
+    "serve": "vite preview --host",
+    "lint": "eslint src --max-warnings 0",
+    "lint:fix": "eslint --fix --max-warnings 0 src"
   },
   "dependencies": {
     "@fontsource/material-icons": "^4.5.4",
diff --git a/src/App.vue b/src/App.vue
index 6a365ef..40e21de 100644
--- a/src/App.vue
+++ b/src/App.vue
@@ -19,7 +19,7 @@ import Error from "components/Error.vue";
 import { jsx } from "features/feature";
 import state from "game/state";
 import { coerceComponent, render } from "util/vue";
-import { CSSProperties, watch } from "vue";
+import { CSSProperties } from "vue";
 import { computed, toRef, unref } from "vue";
 import Game from "./components/Game.vue";
 import GameOverScreen from "./components/GameOverScreen.vue";
diff --git a/src/features/action.tsx b/src/features/action.tsx
index 1fbb8d3..2919a9e 100644
--- a/src/features/action.tsx
+++ b/src/features/action.tsx
@@ -31,7 +31,7 @@ import { coerceComponent, isCoercableComponent, render } from "util/vue";
 import { computed, Ref, ref, unref } from "vue";
 import { BarOptions, createBar, GenericBar } from "./bars/bar";
 import { ClickableOptions } from "./clickables/clickable";
-import { Decorator, GenericDecorator } from "./decorators/common";
+import { GenericDecorator } from "./decorators/common";
 
 /** A symbol used to identify {@link Action} features. */
 export const ActionType = Symbol("Action");
diff --git a/src/features/tooltips/tooltip.ts b/src/features/tooltips/tooltip.ts
index 54d782c..8d65efd 100644
--- a/src/features/tooltips/tooltip.ts
+++ b/src/features/tooltips/tooltip.ts
@@ -1,6 +1,6 @@
 import type { CoercableComponent, GenericComponent, Replace, StyleValue } from "features/feature";
 import { Component, GatherProps, setDefault } from "features/feature";
-import { deletePersistent, Persistent, persistent } from "game/persistence";
+import { persistent } from "game/persistence";
 import { Direction } from "util/common";
 import type {
     Computable,
diff --git a/src/features/trees/tree.ts b/src/features/trees/tree.ts
index da77f60..6d09fc9 100644
--- a/src/features/trees/tree.ts
+++ b/src/features/trees/tree.ts
@@ -1,4 +1,4 @@
-import { Decorator, GenericDecorator } from "features/decorators/common";
+import { GenericDecorator } from "features/decorators/common";
 import type {
     CoercableComponent,
     GenericComponent,
diff --git a/src/game/formulas/operations.ts b/src/game/formulas/operations.ts
index 586319e..7210cfb 100644
--- a/src/game/formulas/operations.ts
+++ b/src/game/formulas/operations.ts
@@ -552,7 +552,9 @@ export function tetrate(
 export function invertTetrate(
     value: DecimalSource,
     base: FormulaSource,
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
     height: FormulaSource,
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
     payload: FormulaSource
 ) {
     if (hasVariable(base)) {
@@ -576,6 +578,7 @@ export function invertIteratedExp(
     value: DecimalSource,
     lhs: FormulaSource,
     height: FormulaSource,
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
     payload: FormulaSource
 ) {
     if (hasVariable(lhs)) {
@@ -626,6 +629,7 @@ export function invertLayeradd(
     value: DecimalSource,
     lhs: FormulaSource,
     diff: FormulaSource,
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
     base: FormulaSource
 ) {
     if (hasVariable(lhs)) {
diff --git a/src/game/modifiers.tsx b/src/game/modifiers.tsx
index 1ee3905..2d2ccdf 100644
--- a/src/game/modifiers.tsx
+++ b/src/game/modifiers.tsx
@@ -296,10 +296,17 @@ export function createSequentialModifier<
                 : undefined,
             getFormula: modifiers.every(m => m.getFormula != null)
                 ? (gain: FormulaSource) =>
-                      modifiers
-                          // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
-                          .reduce((acc, curr) => Formula.if(acc, curr.enabled ?? true,
-                            acc => curr.getFormula!(acc), acc => acc), gain)
+                      modifiers.reduce(
+                          (acc, curr) =>
+                              Formula.if(
+                                  acc,
+                                  curr.enabled ?? true,
+                                  // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+                                  acc => curr.getFormula!(acc),
+                                  acc => acc
+                              ),
+                          gain
+                      )
                 : undefined,
             enabled: modifiers.some(m => m.enabled != null)
                 ? computed(() => modifiers.filter(m => unref(m.enabled) !== false).length > 0)
diff --git a/src/game/requirements.tsx b/src/game/requirements.tsx
index ea82a64..363fccd 100644
--- a/src/game/requirements.tsx
+++ b/src/game/requirements.tsx
@@ -222,7 +222,9 @@ export function createCostRequirement<T extends CostRequirementOptions>(
                 Decimal.gte(
                     req.resource.value,
                     unref(req.cost as ProcessedComputable<DecimalSource>)
-                ) ? 1 : 0
+                )
+                    ? 1
+                    : 0
             );
         }