diff --git a/backend/src/api/controllers/result.ts b/backend/src/api/controllers/result.ts
index 4cc1d286d..16e1c31d1 100644
--- a/backend/src/api/controllers/result.ts
+++ b/backend/src/api/controllers/result.ts
@@ -20,7 +20,7 @@ import Logger from "../../utils/logger";
 import "dotenv/config";
 import { MonkeyResponse } from "../../utils/monkey-response";
 import MonkeyError from "../../utils/error";
-import { isTestTooShort } from "../../utils/validation";
+import { areFunboxesCompatible, isTestTooShort } from "../../utils/validation";
 import {
   implemented as anticheatImplemented,
   validateResult,
@@ -36,7 +36,7 @@ import { getDailyLeaderboard } from "../../utils/daily-leaderboards";
 import AutoRoleList from "../../constants/auto-roles";
 import * as UserDAL from "../../dal/user";
 import { buildMonkeyMail } from "../../utils/monkey-mail";
-import FunboxesMetadata from "../../constants/funbox";
+import FunboxList from "../../constants/funbox-list";
 import _ from "lodash";
 import * as WeeklyXpLeaderboard from "../../services/weekly-xp-leaderboard";
 import { UAParser } from "ua-parser-js";
@@ -175,6 +175,17 @@ export async function addResult(
     }
   }
 
+  if (result.funbox) {
+    const funboxes = result.funbox.split("#");
+    if (funboxes.length !== _.uniq(funboxes).length) {
+      throw new MonkeyError(400, "Duplicate funboxes");
+    }
+  }
+
+  if (!areFunboxesCompatible(result.funbox)) {
+    throw new MonkeyError(400, "Impossible funbox combination");
+  }
+
   try {
     result.keySpacingStats = {
       average:
@@ -625,9 +636,8 @@ async function calculateXp(
   }
 
   if (funboxBonusConfiguration > 0) {
-    const resultFunboxes = _.uniq(funbox.split("#"));
-    const funboxModifier = _.sumBy(resultFunboxes, (funboxName) => {
-      const funbox = FunboxesMetadata[funboxName as string];
+    const funboxModifier = _.sumBy(funbox.split("#"), (funboxName) => {
+      const funbox = FunboxList.find((f) => f.name === funboxName);
       const difficultyLevel = funbox?.difficultyLevel ?? 0;
       return Math.max(difficultyLevel * funboxBonusConfiguration, 0);
     });
diff --git a/backend/src/utils/validation.ts b/backend/src/utils/validation.ts
index bd4f1af6f..39e6c5cd2 100644
--- a/backend/src/utils/validation.ts
+++ b/backend/src/utils/validation.ts
@@ -1,7 +1,8 @@
 import _ from "lodash";
 import { replaceHomoglyphs } from "../constants/homoglyphs";
 import { profanities, regexProfanities } from "../constants/profanities";
-import { matchesAPattern, sanitizeString } from "./misc";
+import { intersect, matchesAPattern, sanitizeString } from "./misc";
+import { default as FunboxList } from "../constants/funbox-list";
 
 export function inRange(value: number, min: number, max: number): boolean {
   return value >= min && value <= max;
@@ -105,3 +106,154 @@ export function isTestTooShort(result: MonkeyTypes.CompletedEvent): boolean {
 
   return false;
 }
+
+export function areFunboxesCompatible(funboxesString: string): boolean {
+  const funboxes = funboxesString.split("#").filter((f) => f !== "none");
+
+  const funboxesToCheck = FunboxList.filter((f) => funboxes.includes(f.name));
+
+  console.log(funboxesToCheck);
+  console.log(funboxes);
+
+  const allFunboxesAreValid = funboxesToCheck.length === funboxes.length;
+  const oneWordModifierMax =
+    funboxesToCheck.filter(
+      (f) =>
+        f.frontendFunctions?.includes("getWord") ||
+        f.frontendFunctions?.includes("pullSection") ||
+        f.frontendFunctions?.includes("withWords")
+    ).length <= 1;
+  const layoutUsability =
+    funboxesToCheck.filter((f) =>
+      f.properties?.find((fp) => fp === "changesLayout")
+    ).length === 0 ||
+    funboxesToCheck.filter((f) =>
+      f.properties?.find((fp) => fp === "ignoresLayout" || fp === "usesLayout")
+    ).length === 0;
+  const oneNospaceOrToPushMax =
+    funboxesToCheck.filter((f) =>
+      f.properties?.find((fp) => fp === "nospace" || fp.startsWith("toPush"))
+    ).length <= 1;
+  const oneChangesWordsVisibilityMax =
+    funboxesToCheck.filter((f) =>
+      f.properties?.find((fp) => fp === "changesWordsVisibility")
+    ).length <= 1;
+  const oneFrequencyChangesMax =
+    funboxesToCheck.filter((f) =>
+      f.properties?.find((fp) => fp === "changesWordsFrequency")
+    ).length <= 1;
+  const noFrequencyChangesConflicts =
+    funboxesToCheck.filter((f) =>
+      f.properties?.find((fp) => fp === "changesWordsFrequency")
+    ).length === 0 ||
+    funboxesToCheck.filter((f) =>
+      f.properties?.find((fp) => fp === "ignoresLanguage")
+    ).length === 0;
+  const capitalisationChangePosibility =
+    funboxesToCheck.filter((f) =>
+      f.properties?.find((fp) => fp === "noLetters")
+    ).length === 0 ||
+    funboxesToCheck.filter((f) =>
+      f.properties?.find((fp) => fp === "changesCapitalisation")
+    ).length === 0;
+  const noConflictsWithSymmetricChars =
+    funboxesToCheck.filter((f) =>
+      f.properties?.find((fp) => fp === "conflictsWithSymmetricChars")
+    ).length === 0 ||
+    funboxesToCheck.filter((f) =>
+      f.properties?.find((fp) => fp === "symmetricChars")
+    ).length === 0;
+  const canSpeak =
+    funboxesToCheck.filter((f) =>
+      f.properties?.find((fp) => fp === "speaks" || fp === "unspeakable")
+    ).length <= 1;
+  const hasLanguageToSpeak =
+    funboxesToCheck.filter((f) => f.properties?.find((fp) => fp === "speaks"))
+      .length === 0 ||
+    funboxesToCheck.filter((f) =>
+      f.properties?.find((fp) => fp === "ignoresLanguage")
+    ).length === 0;
+  const oneToPushOrPullSectionMax =
+    funboxesToCheck.filter(
+      (f) =>
+        f.properties?.find((fp) => fp.startsWith("toPush:")) ||
+        f.frontendFunctions?.includes("pullSection")
+    ).length <= 1;
+  const oneApplyCSSMax =
+    funboxesToCheck.filter((f) => f.frontendFunctions?.includes("applyCSS"))
+      .length <= 1;
+  const onePunctuateWordMax =
+    funboxesToCheck.filter((f) =>
+      f.frontendFunctions?.includes("punctuateWord")
+    ).length <= 1;
+  const oneCharCheckerMax =
+    funboxesToCheck.filter((f) =>
+      f.frontendFunctions?.includes("isCharCorrect")
+    ).length <= 1;
+  const oneCharReplacerMax =
+    funboxesToCheck.filter((f) => f.frontendFunctions?.includes("getWordHtml"))
+      .length <= 1;
+  const allowedConfig = {} as Record<string, string[] | boolean[]>;
+  let noConfigConflicts = true;
+  for (const f of funboxesToCheck) {
+    if (!f.frontendForcedConfig) continue;
+    for (const key in f.frontendForcedConfig) {
+      if (allowedConfig[key]) {
+        if (
+          intersect<string | boolean>(
+            allowedConfig[key],
+            f.frontendForcedConfig[key],
+            true
+          ).length === 0
+        ) {
+          noConfigConflicts = false;
+          break;
+        }
+      } else {
+        allowedConfig[key] = f.frontendForcedConfig[key];
+      }
+    }
+  }
+
+  console.log(allowedConfig);
+
+  console.log(
+    allFunboxesAreValid,
+    oneWordModifierMax,
+    layoutUsability,
+    oneNospaceOrToPushMax,
+    oneChangesWordsVisibilityMax,
+    oneFrequencyChangesMax,
+    noFrequencyChangesConflicts,
+    capitalisationChangePosibility,
+    noConflictsWithSymmetricChars,
+    canSpeak,
+    hasLanguageToSpeak,
+    oneToPushOrPullSectionMax,
+    oneApplyCSSMax,
+    onePunctuateWordMax,
+    oneCharCheckerMax,
+    oneCharReplacerMax,
+    noConfigConflicts
+  );
+
+  return (
+    allFunboxesAreValid &&
+    oneWordModifierMax &&
+    layoutUsability &&
+    oneNospaceOrToPushMax &&
+    oneChangesWordsVisibilityMax &&
+    oneFrequencyChangesMax &&
+    noFrequencyChangesConflicts &&
+    capitalisationChangePosibility &&
+    noConflictsWithSymmetricChars &&
+    canSpeak &&
+    hasLanguageToSpeak &&
+    oneToPushOrPullSectionMax &&
+    oneApplyCSSMax &&
+    onePunctuateWordMax &&
+    oneCharCheckerMax &&
+    oneCharReplacerMax &&
+    noConfigConflicts
+  );
+}