diff --git a/app/game-engine/src/turn/reservedTurnHandler.ts b/app/game-engine/src/turn/reservedTurnHandler.ts
index ca232db..cdb5a53 100644
--- a/app/game-engine/src/turn/reservedTurnHandler.ts
+++ b/app/game-engine/src/turn/reservedTurnHandler.ts
@@ -22,7 +22,7 @@ import {
     resolveGeneralAction,
 } from '@sammo-ts/logic';
 import { LogCategory, LogFormat, LogScope } from '@sammo-ts/logic';
-import { asRecord, LiteHashDRBG } from '@sammo-ts/common';
+import { asRecord, LiteHashDRBG, RandUtil } from '@sammo-ts/common';
 
 import type { ConstraintContext, StateView } from '@sammo-ts/logic';
 
@@ -76,31 +76,6 @@ const serializeSeed = (...values: Array<string | number>): string =>
         .map((value) => (typeof value === 'string' ? `str(${value.length},${value})` : `int(${Math.floor(value)})`))
         .join('|');
 
-class DeterministicRandom {
-    constructor(private readonly rng: LiteHashDRBG) {}
-
-    nextFloat(): number {
-        return this.rng.nextFloat1();
-    }
-
-    nextBool(probability: number): boolean {
-        if (probability >= 1) {
-            return true;
-        }
-        if (probability <= 0) {
-            return false;
-        }
-        return this.nextFloat() < probability;
-    }
-
-    nextInt(minInclusive: number, maxExclusive: number): number {
-        const span = maxExclusive - minInclusive;
-        if (span <= 1) {
-            return minInclusive;
-        }
-        return minInclusive + this.rng.nextInt(span - 1);
-    }
-}
 
 type WorldView = {
     getGeneralById(id: number): TurnGeneral | null;
@@ -539,7 +514,7 @@ export const createReservedTurnHandler = async (options: {
                         context.world.currentMonth,
                         currentGeneral.id
                     );
-                    return new DeterministicRandom(new LiteHashDRBG(rngSeed));
+                    return new RandUtil(new LiteHashDRBG(rngSeed));
                 };
 
                 const actionArgsRecord = extractArgsRecord(actionArgs);
diff --git a/packages/common/src/rng.ts b/packages/common/src/rng.ts
index 44871de..cbbf936 100644
--- a/packages/common/src/rng.ts
+++ b/packages/common/src/rng.ts
@@ -1,5 +1,5 @@
 export interface RandomGenerator {
-    nextFloat(): number;
+    nextFloat1(): number;
     nextBool(probability: number): boolean;
     nextInt(minInclusive: number, maxExclusive: number): number;
 }
diff --git a/packages/common/src/util/RandUtil.ts b/packages/common/src/util/RandUtil.ts
index 65cc0db..a308b07 100644
--- a/packages/common/src/util/RandUtil.ts
+++ b/packages/common/src/util/RandUtil.ts
@@ -13,13 +13,17 @@ export class RandUtil {
         return this.nextFloat1() * range + min;
     }
 
-    public nextRangeInt(min: number, max: number): number {
-        const range = max - min;
-        return this.rng.nextInt(range) + min;
+    public nextRangeInt(minInclusive: number, maxInclusive: number): number {
+        const range = maxInclusive - minInclusive;
+        return this.rng.nextInt(range) + minInclusive;
     }
 
-    public nextInt(max?: number): number {
-        return this.rng.nextInt(max);
+    public nextInt(minInclusive: number, maxExclusive: number): number {
+        const span = maxExclusive - minInclusive;
+        if (span <= 1) {
+            return minInclusive;
+        }
+        return minInclusive + this.rng.nextInt(span - 1);
     }
 
     public nextBit(): boolean {
diff --git a/packages/logic/src/actions/turn/actionContext.ts b/packages/logic/src/actions/turn/actionContext.ts
index 193fe82..473a30a 100644
--- a/packages/logic/src/actions/turn/actionContext.ts
+++ b/packages/logic/src/actions/turn/actionContext.ts
@@ -4,7 +4,7 @@ import type { ScenarioMeta } from '@sammo-ts/logic/world/types.js';
 import type { MapDefinition, UnitSetDefinition } from '@sammo-ts/logic/world/types.js';
 
 export interface ActionRandomSource {
-    nextFloat(): number;
+    nextFloat1(): number;
     nextBool(probability: number): boolean;
     nextInt(minInclusive: number, maxExclusive: number): number;
 }
diff --git a/packages/logic/src/actions/turn/general/che_견문.ts b/packages/logic/src/actions/turn/general/che_견문.ts
index d670e0d..8923c3d 100644
--- a/packages/logic/src/actions/turn/general/che_견문.ts
+++ b/packages/logic/src/actions/turn/general/che_견문.ts
@@ -132,7 +132,7 @@ const pickByWeight = (rng: GeneralActionResolveContext['rng']): { flags: number;
         const text = base.texts[0] ?? '';
         return { flags: base.flags, text };
     }
-    let cursor = rng.nextFloat() * total;
+    let cursor = rng.nextFloat1() * total;
     for (const entry of SIGHTSEEING_MESSAGES) {
         const weight = Math.max(entry.weight, 0);
         cursor -= weight;
diff --git a/packages/logic/src/actions/turn/general/che_단련.ts b/packages/logic/src/actions/turn/general/che_단련.ts
index cc2393b..a055b1a 100644
--- a/packages/logic/src/actions/turn/general/che_단련.ts
+++ b/packages/logic/src/actions/turn/general/che_단련.ts
@@ -47,7 +47,7 @@ const pickByWeight = <T extends string>(rng: DrillContext['rng'], weights: Recor
     if (total <= 0) {
         return first[0];
     }
-    let cursor = rng.nextFloat() * total;
+    let cursor = rng.nextFloat1() * total;
     for (const [key, weight] of entries) {
         if (weight <= 0) {
             continue;
diff --git a/packages/logic/src/actions/turn/general/che_랜덤임관.ts b/packages/logic/src/actions/turn/general/che_랜덤임관.ts
index e9a3fbc..59ae627 100644
--- a/packages/logic/src/actions/turn/general/che_랜덤임관.ts
+++ b/packages/logic/src/actions/turn/general/che_랜덤임관.ts
@@ -91,7 +91,7 @@ const pickUsingWeightPair = <T>(rng: RandomGenerator, items: Array<[T, number]>)
     if (total <= 0) {
         return items[0]?.[0] ?? null;
     }
-    let cursor = rng.nextFloat() * total;
+    let cursor = rng.nextFloat1() * total;
     for (const [item, weight] of items) {
         if (weight <= 0) {
             continue;
diff --git a/packages/logic/src/actions/turn/general/che_물자조달.ts b/packages/logic/src/actions/turn/general/che_물자조달.ts
index b20d949..80f95dd 100644
--- a/packages/logic/src/actions/turn/general/che_물자조달.ts
+++ b/packages/logic/src/actions/turn/general/che_물자조달.ts
@@ -53,7 +53,7 @@ export class ActionResolver<
         // For now, assume simplified or no bonus unless strictly required to port helper.
         // Assuming 1.0 for now if helper not available, or implement simple bonus.
         // Legacy: $score *= $rng->nextRange(0.8, 1.2);
-        score *= context.rng.nextFloat() * 0.4 + 0.8;
+        score *= context.rng.nextFloat1() * 0.4 + 0.8;
 
         // 3. Success/Fail Ratio
         let successRatio = 0.1;
@@ -63,7 +63,7 @@ export class ActionResolver<
         failRatio = this.pipeline.onCalcDomestic(context, '조달', 'fail', failRatio);
 
         // 4. Determine Outcome
-        const roll = context.rng.nextFloat();
+        const roll = context.rng.nextFloat1();
         let outcome: 'fail' | 'success' | 'normal' = 'normal';
 
         if (roll < failRatio) {
@@ -95,7 +95,7 @@ export class ActionResolver<
         // Stat Exp
         // Legacy: choose weighted among L/S/I
         const statChoice =
-            context.rng.nextFloat() * (general.stats.leadership + general.stats.strength + general.stats.intelligence);
+            context.rng.nextFloat1() * (general.stats.leadership + general.stats.strength + general.stats.intelligence);
         let statKey: 'leadership_exp' | 'strength_exp' | 'intel_exp' = 'leadership_exp';
 
         if (statChoice < general.stats.leadership) {
diff --git a/packages/logic/src/actions/turn/general/che_상업투자.ts b/packages/logic/src/actions/turn/general/che_상업투자.ts
index b12e873..45e1caa 100644
--- a/packages/logic/src/actions/turn/general/che_상업투자.ts
+++ b/packages/logic/src/actions/turn/general/che_상업투자.ts
@@ -68,14 +68,14 @@ const getMetaNumber = (meta: Record<string, unknown>, key: string): number | nul
     return typeof raw === 'number' ? raw : null;
 };
 
-const randomRange = (rng: RandomGenerator, min: number, max: number): number => min + (max - min) * rng.nextFloat();
+const randomRange = (rng: RandomGenerator, min: number, max: number): number => min + (max - min) * rng.nextFloat1();
 
 const pickByWeight = (rng: RandomGenerator, weights: Record<DomesticCriticalPick, number>): DomesticCriticalPick => {
     const total = weights.fail + weights.normal + weights.success;
     if (total <= 0) {
         return 'normal';
     }
-    let cursor = rng.nextFloat() * total;
+    let cursor = rng.nextFloat1() * total;
     for (const key of ['fail', 'normal', 'success'] as const) {
         cursor -= weights[key];
         if (cursor <= 0) {
diff --git a/packages/logic/src/actions/turn/general/che_인재탐색.ts b/packages/logic/src/actions/turn/general/che_인재탐색.ts
index 7e4b8e6..22cd06e 100644
--- a/packages/logic/src/actions/turn/general/che_인재탐색.ts
+++ b/packages/logic/src/actions/turn/general/che_인재탐색.ts
@@ -114,7 +114,7 @@ const pickByWeight = <T extends string>(rng: RandomGenerator, weights: Record<T,
     if (total <= 0) {
         return first[0];
     }
-    let cursor = rng.nextFloat() * total;
+    let cursor = rng.nextFloat1() * total;
     for (const [key, weight] of entries) {
         if (weight <= 0) {
             continue;
diff --git a/packages/logic/src/actions/turn/general/che_주민선정.ts b/packages/logic/src/actions/turn/general/che_주민선정.ts
index abd100c..80d8546 100644
--- a/packages/logic/src/actions/turn/general/che_주민선정.ts
+++ b/packages/logic/src/actions/turn/general/che_주민선정.ts
@@ -47,7 +47,7 @@ const addMetaNumber = (meta: Record<string, unknown>, key: string, delta: number
     return { ...meta, [key]: current + delta };
 };
 
-const randomRange = (rng: RandomGenerator, min: number, max: number): number => min + (max - min) * rng.nextFloat();
+const randomRange = (rng: RandomGenerator, min: number, max: number): number => min + (max - min) * rng.nextFloat1();
 
 const remainCityTrust = (): Constraint => ({
     name: 'remainCityTrust',
diff --git a/packages/logic/src/tournament/battle.ts b/packages/logic/src/tournament/battle.ts
index 94abd91..c8b0818 100644
--- a/packages/logic/src/tournament/battle.ts
+++ b/packages/logic/src/tournament/battle.ts
@@ -68,16 +68,16 @@ export const resolveTournamentBattle = (input: TournamentBattleInput): Tournamen
     let selected = 2;
 
     for (let phase = 1; phase <= maxTurns; phase += 1) {
-        const baseDamageAttacker = round(defenderStat * (rng.nextInt(21) + 90) / 130);
-        const baseDamageDefender = round(attackerStat * (rng.nextInt(21) + 90) / 130);
+        const baseDamageAttacker = round(defenderStat * (rng.nextInt(0, 22) + 90) / 130);
+        const baseDamageDefender = round(attackerStat * (rng.nextInt(0, 22) + 90) / 130);
         let damageAttacker = baseDamageAttacker;
         let damageDefender = baseDamageDefender;
 
-        if (attackerStat >= rng.nextInt(100)) {
-            damageDefender += round(attackerStat * (rng.nextInt(41) + 10) / 130);
+        if (attackerStat >= rng.nextInt(0, 101)) {
+            damageDefender += round(attackerStat * (rng.nextInt(0, 42) + 10) / 130);
         }
-        if (defenderStat >= rng.nextInt(100)) {
-            damageAttacker += round(defenderStat * (rng.nextInt(41) + 10) / 130);
+        if (defenderStat >= rng.nextInt(0, 101)) {
+            damageAttacker += round(defenderStat * (rng.nextInt(0, 42) + 10) / 130);
         }
 
         let criticalAttacker = false;
@@ -85,13 +85,13 @@ export const resolveTournamentBattle = (input: TournamentBattleInput): Tournamen
         let factorAttacker = 1;
         let factorDefender = 1;
 
-        if (energyBaseAttacker / 5 > energyAttacker && damageAttacker > damageDefender && attackerStat >= rng.nextInt(300)) {
-            factorDefender = round((rng.nextInt(301) + 200) / 100);
+        if (energyBaseAttacker / 5 > energyAttacker && damageAttacker > damageDefender && attackerStat >= rng.nextInt(0, 301)) {
+            factorDefender = round((rng.nextInt(0, 302) + 200) / 100);
             criticalAttacker = true;
             log.push(`<S>●</> <Y>${attacker.name}</>의 분노의 일격!`);
         }
-        if (energyBaseDefender / 5 > energyDefender && damageDefender > damageAttacker && defenderStat >= rng.nextInt(300)) {
-            factorAttacker = round((rng.nextInt(301) + 200) / 100);
+        if (energyBaseDefender / 5 > energyDefender && damageDefender > damageAttacker && defenderStat >= rng.nextInt(0, 301)) {
+            factorAttacker = round((rng.nextInt(0, 302) + 200) / 100);
             criticalDefender = true;
             log.push(`<S>●</> <Y>${defender.name}</>의 분노의 일격!`);
         }
@@ -100,18 +100,18 @@ export const resolveTournamentBattle = (input: TournamentBattleInput): Tournamen
         damageDefender = round(damageDefender * factorDefender);
 
         if (phase === 1) {
-            if (attackerStat * 0.9 > defenderStat && attackerStat >= rng.nextInt(400)) {
-                damageDefender += round(attackerStat * (rng.nextInt(31) + 70) / 100);
+            if (attackerStat * 0.9 > defenderStat && attackerStat >= rng.nextInt(0, 401)) {
+                damageDefender += round(attackerStat * (rng.nextInt(0, 32) + 70) / 100);
             }
-            if (defenderStat * 0.9 > attackerStat && defenderStat >= rng.nextInt(400)) {
-                damageAttacker += round(defenderStat * (rng.nextInt(31) + 70) / 100);
+            if (defenderStat * 0.9 > attackerStat && defenderStat >= rng.nextInt(0, 401)) {
+                damageAttacker += round(defenderStat * (rng.nextInt(0, 32) + 70) / 100);
             }
         } else {
-            if (!criticalAttacker && attackerStat >= rng.nextInt(1000)) {
-                damageDefender += round(attackerStat * (rng.nextInt(31) + 20) / 100);
+            if (!criticalAttacker && attackerStat >= rng.nextInt(0, 1001)) {
+                damageDefender += round(attackerStat * (rng.nextInt(0, 32) + 20) / 100);
             }
-            if (!criticalDefender && defenderStat >= rng.nextInt(1000)) {
-                damageAttacker += round(defenderStat * (rng.nextInt(31) + 20) / 100);
+            if (!criticalDefender && defenderStat >= rng.nextInt(0, 1001)) {
+                damageAttacker += round(defenderStat * (rng.nextInt(0, 32) + 20) / 100);
             }
         }
 
diff --git a/packages/logic/test/dispatchWarAction.test.ts b/packages/logic/test/dispatchWarAction.test.ts
index 3d296b0..3e02f61 100644
--- a/packages/logic/test/dispatchWarAction.test.ts
+++ b/packages/logic/test/dispatchWarAction.test.ts
@@ -166,7 +166,7 @@ const aftermathConfig: WarAftermathConfig = {
 };
 
 const rng = {
-    nextFloat: () => 0.1,
+    nextFloat1: () => 0.1,
     nextBool: (probability: number) => probability >= 0.1,
     nextInt: (minInclusive: number, _maxExclusive: number) => minInclusive,
 };
diff --git a/packages/logic/test/scenarios/general_commands_new.test.ts b/packages/logic/test/scenarios/general_commands_new.test.ts
index 31d679d..445925e 100644
--- a/packages/logic/test/scenarios/general_commands_new.test.ts
+++ b/packages/logic/test/scenarios/general_commands_new.test.ts
@@ -175,7 +175,7 @@ describe('General Commands New Scenario', () => {
                         nextBool: () => true,
                         nextRange: (_min: number, max: number) => max,
                         nextRangeInt: (_min: number, max: number) => max,
-                        nextFloat: () => 0.9, // Ensure success
+                        nextFloat1: () => 0.9, // Ensure success
                     },
                 },
             },
diff --git a/packages/logic/test/scenarios/reservedTurnExecution.test.ts b/packages/logic/test/scenarios/reservedTurnExecution.test.ts
index 62a8f91..ae89955 100644
--- a/packages/logic/test/scenarios/reservedTurnExecution.test.ts
+++ b/packages/logic/test/scenarios/reservedTurnExecution.test.ts
@@ -121,7 +121,7 @@ class ReservedTurnRunner extends TestGameRunner {
 
                 // Simple RNG mock
                 const rng: RandomGenerator = {
-                    nextFloat: () => 0.5,
+                    nextFloat1: () => 0.5,
                     nextBool: () => true,
                     nextInt: (min: number, _max: number) => min,
                 };
diff --git a/packages/logic/test/specialActions.test.ts b/packages/logic/test/specialActions.test.ts
index 217322c..27e523f 100644
--- a/packages/logic/test/specialActions.test.ts
+++ b/packages/logic/test/specialActions.test.ts
@@ -229,7 +229,7 @@ describe('trait modules', () => {
             listGenerals: () => [general, patient],
         };
         const rng: RandomGenerator = {
-            nextFloat: () => 0,
+            nextFloat1: () => 0,
             nextBool: () => true,
             nextInt: (minInclusive: number, _maxExclusive: number) => minInclusive,
         };
diff --git a/packages/logic/test/testEnv.ts b/packages/logic/test/testEnv.ts
index 59be9a0..628ea7f 100644
--- a/packages/logic/test/testEnv.ts
+++ b/packages/logic/test/testEnv.ts
@@ -211,7 +211,7 @@ export class TestGameRunner {
                     nextBool: () => Math.random() < 0.5,
                     nextRange: (min: number, max: number) => Math.random() * (max - min) + min,
                     nextRangeInt: (min: number, max: number) => Math.floor(Math.random() * (max - min)) + min,
-                    nextFloat: () => Math.random(),
+                    nextFloat1: () => Math.random(),
                 } as any,
 
                 year: this.currentDate.getFullYear(),