diff --git a/src/models/interaction.ts b/src/models/interaction.ts
index 5e6c6c5..a8fedd6 100644
--- a/src/models/interaction.ts
+++ b/src/models/interaction.ts
@@ -1,11 +1,23 @@
-import { hoverEdge, hoverNode, selectEdge, selectNode, unhoverAll, unselectAll } from '../utils/graph.utils';
+import {
+  hoverEdge,
+  hoverNode,
+  ISelectionOptions,
+  selectEdge,
+  selectNode,
+  unhoverAll,
+  unselectAll,
+  unselectEdge,
+  unselectNode,
+} from '../utils/graph.utils';
 import { IEdgeBase } from './edge';
 import { IGraph } from './graph';
 import { INodeBase } from './node';
 
 export interface IGraphInteraction {
-  selectNodeById(id: any): boolean;
-  selectEdgeById(id: any): boolean;
+  selectNodeById(id: any, options?: ISelectionOptions): boolean;
+  selectEdgeById(id: any, options?: ISelectionOptions): boolean;
+  unselectNodeById(id: any, options?: ISelectionOptions): boolean;
+  unselectEdgeById(id: any, options?: ISelectionOptions): boolean;
   unselectAll(): number;
   hoverNodeById(id: any): boolean;
   hoverEdgeById(id: any): boolean;
@@ -19,21 +31,39 @@ export class GraphInteraction<N extends INodeBase, E extends IEdgeBase> implemen
     this._graph = graph;
   }
 
-  selectNodeById(id: any): boolean {
+  selectNodeById(id: any, options?: ISelectionOptions): boolean {
     const node = this._graph.getNodeById(id);
     if (!node) {
       return false;
     }
-    selectNode(node);
+    selectNode(node, options);
     return true;
   }
 
-  selectEdgeById(id: any): boolean {
+  selectEdgeById(id: any, options?: ISelectionOptions): boolean {
     const edge = this._graph.getEdgeById(id);
     if (!edge) {
       return false;
     }
-    selectEdge(edge);
+    selectEdge(edge, options);
+    return true;
+  }
+
+  unselectNodeById(id: any, options?: ISelectionOptions): boolean {
+    const node = this._graph.getNodeById(id);
+    if (!node) {
+      return false;
+    }
+    unselectNode(node, options);
+    return true;
+  }
+
+  unselectEdgeById(id: any, options?: ISelectionOptions): boolean {
+    const edge = this._graph.getEdgeById(id);
+    if (!edge) {
+      return false;
+    }
+    unselectEdge(edge, options);
     return true;
   }
 
diff --git a/src/models/strategy.ts b/src/models/strategy.ts
index a3580b6..2eb7c36 100644
--- a/src/models/strategy.ts
+++ b/src/models/strategy.ts
@@ -2,11 +2,21 @@ import { INode, INodeBase } from './node';
 import { IEdge, IEdgeBase } from './edge';
 import { IGraph } from './graph';
 import { IPosition } from '../common';
-import { hoverOnlyNode, selectOnlyEdge, selectOnlyNode, unhoverAll, unselectAll } from '../utils/graph.utils';
+import {
+  hoverOnlyNode,
+  selectOnlyEdge,
+  selectOnlyNode,
+  toggleEdgeSelection,
+  toggleNodeSelection,
+  unhoverAll,
+  unselectAll,
+} from '../utils/graph.utils';
 
 export interface IEventStrategySettings {
   isDefaultSelectEnabled: boolean;
   isDefaultHoverEnabled: boolean;
+  isDefaultMultiSelectEnabled: boolean;
+  isDefaultSelectCascadeEnabled: boolean;
 }
 
 export interface IEventStrategyResponse<N extends INodeBase, E extends IEdgeBase> {
@@ -14,10 +24,20 @@ export interface IEventStrategyResponse<N extends INodeBase, E extends IEdgeBase
   changedSubject?: INode<N, E> | IEdge<N, E>;
 }
 
+export interface IEventStrategyClickOptions {
+  isAppend?: boolean;
+}
+
 export interface IEventStrategy<N extends INodeBase, E extends IEdgeBase> {
   isSelectEnabled: boolean;
   isHoverEnabled: boolean;
-  onMouseClick: (graph: IGraph<N, E>, point: IPosition) => IEventStrategyResponse<N, E>;
+  isMultiSelectEnabled: boolean;
+  isSelectCascadeEnabled: boolean;
+  onMouseClick: (
+    graph: IGraph<N, E>,
+    point: IPosition,
+    options?: IEventStrategyClickOptions,
+  ) => IEventStrategyResponse<N, E>;
   onMouseMove: (graph: IGraph<N, E>, point: IPosition) => IEventStrategyResponse<N, E>;
   onMouseRightClick: (graph: IGraph<N, E>, point: IPosition) => IEventStrategyResponse<N, E>;
   onMouseDoubleClick: (graph: IGraph<N, E>, point: IPosition) => IEventStrategyResponse<N, E>;
@@ -27,17 +47,31 @@ export class DefaultEventStrategy<N extends INodeBase, E extends IEdgeBase> impl
   private _lastHoveredNode?: INode<N, E>;
   public isSelectEnabled: boolean;
   public isHoverEnabled: boolean;
+  public isMultiSelectEnabled: boolean;
+  public isSelectCascadeEnabled: boolean;
 
   constructor(settings: IEventStrategySettings) {
     this.isSelectEnabled = settings.isDefaultSelectEnabled;
     this.isHoverEnabled = settings.isDefaultHoverEnabled;
+    this.isMultiSelectEnabled = settings.isDefaultMultiSelectEnabled;
+    this.isSelectCascadeEnabled = settings.isDefaultSelectCascadeEnabled;
   }
 
-  onMouseClick(graph: IGraph<N, E>, point: IPosition): IEventStrategyResponse<N, E> {
+  onMouseClick(
+    graph: IGraph<N, E>,
+    point: IPosition,
+    options?: IEventStrategyClickOptions,
+  ): IEventStrategyResponse<N, E> {
+    const isAppend = this.isMultiSelectEnabled && (options?.isAppend ?? false);
+
     const node = graph.getNearestNode(point);
     if (node) {
       if (this.isSelectEnabled) {
-        selectOnlyNode(graph, node);
+        if (isAppend) {
+          toggleNodeSelection(node);
+        } else {
+          selectOnlyNode(graph, node, { cascade: this.isSelectCascadeEnabled });
+        }
       }
 
       return {
@@ -49,7 +83,11 @@ export class DefaultEventStrategy<N extends INodeBase, E extends IEdgeBase> impl
     const edge = graph.getNearestEdge(point);
     if (edge) {
       if (this.isSelectEnabled) {
-        selectOnlyEdge(graph, edge);
+        if (isAppend) {
+          toggleEdgeSelection(edge);
+        } else {
+          selectOnlyEdge(graph, edge, { cascade: this.isSelectCascadeEnabled });
+        }
       }
 
       return {
@@ -58,7 +96,7 @@ export class DefaultEventStrategy<N extends INodeBase, E extends IEdgeBase> impl
       };
     }
 
-    if (!this.isSelectEnabled) {
+    if (!this.isSelectEnabled || isAppend) {
       return { isStateChanged: false };
     }
 
@@ -104,7 +142,7 @@ export class DefaultEventStrategy<N extends INodeBase, E extends IEdgeBase> impl
     const node = graph.getNearestNode(point);
     if (node) {
       if (this.isSelectEnabled) {
-        selectOnlyNode(graph, node);
+        selectOnlyNode(graph, node, { cascade: this.isSelectCascadeEnabled });
       }
 
       return {
@@ -116,7 +154,7 @@ export class DefaultEventStrategy<N extends INodeBase, E extends IEdgeBase> impl
     const edge = graph.getNearestEdge(point);
     if (edge) {
       if (this.isSelectEnabled) {
-        selectOnlyEdge(graph, edge);
+        selectOnlyEdge(graph, edge, { cascade: this.isSelectCascadeEnabled });
       }
 
       return {
@@ -139,7 +177,7 @@ export class DefaultEventStrategy<N extends INodeBase, E extends IEdgeBase> impl
     const node = graph.getNearestNode(point);
     if (node) {
       if (this.isSelectEnabled) {
-        selectOnlyNode(graph, node);
+        selectOnlyNode(graph, node, { cascade: this.isSelectCascadeEnabled });
       }
 
       return {
@@ -151,7 +189,7 @@ export class DefaultEventStrategy<N extends INodeBase, E extends IEdgeBase> impl
     const edge = graph.getNearestEdge(point);
     if (edge) {
       if (this.isSelectEnabled) {
-        selectOnlyEdge(graph, edge);
+        selectOnlyEdge(graph, edge, { cascade: this.isSelectCascadeEnabled });
       }
 
       return {
diff --git a/src/utils/graph.utils.ts b/src/utils/graph.utils.ts
index b969614..6d0765f 100644
--- a/src/utils/graph.utils.ts
+++ b/src/utils/graph.utils.ts
@@ -6,22 +6,86 @@ import { IFitZoomTransformOptions } from '../renderer/shared';
 import { ILayoutSettings } from '../simulator';
 import { IHierarchicalLayoutOptions } from '../simulator/engine/shared';
 
-export const selectNode = <N extends INodeBase, E extends IEdgeBase>(node: INode<N, E>) => {
-  setNodeState(node, GraphObjectState.SELECTED, { isStateOverride: true });
+export interface ISelectionOptions {
+  cascade?: boolean;
+}
+
+export const selectNode = <N extends INodeBase, E extends IEdgeBase>(
+  node: INode<N, E>,
+  options?: ISelectionOptions,
+) => {
+  if (options?.cascade ?? true) {
+    setNodeState(node, GraphObjectState.SELECTED, { isStateOverride: true });
+  } else {
+    node.setState(GraphObjectState.SELECTED, { isNotifySkipped: true });
+  }
+};
+
+export const selectEdge = <N extends INodeBase, E extends IEdgeBase>(
+  edge: IEdge<N, E>,
+  options?: ISelectionOptions,
+) => {
+  if (options?.cascade ?? true) {
+    setEdgeState(edge, GraphObjectState.SELECTED, { isStateOverride: true });
+  } else {
+    edge.setState(GraphObjectState.SELECTED, { isNotifySkipped: true });
+  }
+};
+
+export const unselectNode = <N extends INodeBase, E extends IEdgeBase>(
+  node: INode<N, E>,
+  options?: ISelectionOptions,
+) => {
+  if (options?.cascade ?? true) {
+    setNodeState(node, GraphObjectState.NONE, { isStateOverride: true });
+  } else {
+    node.clearState();
+  }
 };
 
-export const selectEdge = <N extends INodeBase, E extends IEdgeBase>(edge: IEdge<N, E>) => {
-  setEdgeState(edge, GraphObjectState.SELECTED, { isStateOverride: true });
+export const unselectEdge = <N extends INodeBase, E extends IEdgeBase>(
+  edge: IEdge<N, E>,
+  options?: ISelectionOptions,
+) => {
+  if (options?.cascade ?? true) {
+    setEdgeState(edge, GraphObjectState.NONE, { isStateOverride: true });
+  } else {
+    edge.clearState();
+  }
 };
 
-export const selectOnlyNode = <N extends INodeBase, E extends IEdgeBase>(graph: IGraph<N, E>, node: INode<N, E>) => {
+export const selectOnlyNode = <N extends INodeBase, E extends IEdgeBase>(
+  graph: IGraph<N, E>,
+  node: INode<N, E>,
+  options?: ISelectionOptions,
+) => {
   unselectAll(graph);
-  selectNode(node);
+  selectNode(node, options);
 };
 
-export const selectOnlyEdge = <N extends INodeBase, E extends IEdgeBase>(graph: IGraph<N, E>, edge: IEdge<N, E>) => {
+export const selectOnlyEdge = <N extends INodeBase, E extends IEdgeBase>(
+  graph: IGraph<N, E>,
+  edge: IEdge<N, E>,
+  options?: ISelectionOptions,
+) => {
   unselectAll(graph);
-  selectEdge(edge);
+  selectEdge(edge, options);
+};
+
+export const toggleNodeSelection = <N extends INodeBase, E extends IEdgeBase>(node: INode<N, E>) => {
+  if (node.isSelected()) {
+    unselectNode(node, { cascade: false });
+  } else {
+    selectNode(node, { cascade: false });
+  }
+};
+
+export const toggleEdgeSelection = <N extends INodeBase, E extends IEdgeBase>(edge: IEdge<N, E>) => {
+  if (edge.isSelected()) {
+    unselectEdge(edge, { cascade: false });
+  } else {
+    selectEdge(edge, { cascade: false });
+  }
 };
 
 export const unselectAll = <N extends INodeBase, E extends IEdgeBase>(
diff --git a/src/views/orb-map-view.ts b/src/views/orb-map-view.ts
index 91b0f4f..5d59819 100644
--- a/src/views/orb-map-view.ts
+++ b/src/views/orb-map-view.ts
@@ -108,6 +108,8 @@ export class OrbMapView<N extends INodeBase, E extends IEdgeBase> implements IOr
       strategy: {
         isDefaultHoverEnabled: true,
         isDefaultSelectEnabled: true,
+        isDefaultMultiSelectEnabled: false,
+        isDefaultSelectCascadeEnabled: true,
         ...settings?.strategy,
       },
     };
@@ -115,6 +117,8 @@ export class OrbMapView<N extends INodeBase, E extends IEdgeBase> implements IOr
     this._strategy = new DefaultEventStrategy<N, E>({
       isDefaultSelectEnabled: this._settings.strategy.isDefaultSelectEnabled ?? false,
       isDefaultHoverEnabled: this._settings.strategy.isDefaultHoverEnabled ?? false,
+      isDefaultMultiSelectEnabled: this._settings.strategy.isDefaultMultiSelectEnabled ?? true,
+      isDefaultSelectCascadeEnabled: this._settings.strategy.isDefaultSelectCascadeEnabled ?? true,
     });
 
     try {
@@ -201,6 +205,16 @@ export class OrbMapView<N extends INodeBase, E extends IEdgeBase> implements IOr
         this._settings.strategy.isDefaultSelectEnabled = settings.strategy.isDefaultSelectEnabled;
         this._strategy.isSelectEnabled = this._settings.strategy.isDefaultSelectEnabled;
       }
+
+      if (isBoolean(settings.strategy.isDefaultMultiSelectEnabled)) {
+        this._settings.strategy.isDefaultMultiSelectEnabled = settings.strategy.isDefaultMultiSelectEnabled;
+        this._strategy.isMultiSelectEnabled = this._settings.strategy.isDefaultMultiSelectEnabled;
+      }
+
+      if (isBoolean(settings.strategy.isDefaultSelectCascadeEnabled)) {
+        this._settings.strategy.isDefaultSelectCascadeEnabled = settings.strategy.isDefaultSelectCascadeEnabled;
+        this._strategy.isSelectCascadeEnabled = this._settings.strategy.isDefaultSelectCascadeEnabled;
+      }
     }
   }
 
@@ -349,7 +363,9 @@ export class OrbMapView<N extends INodeBase, E extends IEdgeBase> implements IOr
           this._renderer.render(this._graph);
         }
       } else if (event.type === 'click') {
-        const response = this._strategy.onMouseClick(this._graph, point);
+        const response = this._strategy.onMouseClick(this._graph, point, {
+          isAppend: event.originalEvent.shiftKey,
+        });
         const subject = response.changedSubject;
 
         if (subject) {
diff --git a/src/views/orb-view.ts b/src/views/orb-view.ts
index 532d38e..61b1efc 100644
--- a/src/views/orb-view.ts
+++ b/src/views/orb-view.ts
@@ -85,6 +85,8 @@ export class OrbView<N extends INodeBase, E extends IEdgeBase> implements IOrbVi
       strategy: {
         isDefaultHoverEnabled: true,
         isDefaultSelectEnabled: true,
+        isDefaultMultiSelectEnabled: false,
+        isDefaultSelectCascadeEnabled: true,
         ...settings?.strategy,
       },
       interaction: {
@@ -110,6 +112,8 @@ export class OrbView<N extends INodeBase, E extends IEdgeBase> implements IOrbVi
     this._strategy = new DefaultEventStrategy<N, E>({
       isDefaultSelectEnabled: this._settings.strategy.isDefaultSelectEnabled ?? false,
       isDefaultHoverEnabled: this._settings.strategy.isDefaultHoverEnabled ?? false,
+      isDefaultMultiSelectEnabled: this._settings.strategy.isDefaultMultiSelectEnabled ?? true,
+      isDefaultSelectCascadeEnabled: this._settings.strategy.isDefaultSelectCascadeEnabled ?? true,
     });
 
     try {
@@ -249,6 +253,16 @@ export class OrbView<N extends INodeBase, E extends IEdgeBase> implements IOrbVi
         this._settings.strategy.isDefaultSelectEnabled = settings.strategy.isDefaultSelectEnabled;
         this._strategy.isSelectEnabled = this._settings.strategy.isDefaultSelectEnabled;
       }
+
+      if (isBoolean(settings.strategy.isDefaultMultiSelectEnabled)) {
+        this._settings.strategy.isDefaultMultiSelectEnabled = settings.strategy.isDefaultMultiSelectEnabled;
+        this._strategy.isMultiSelectEnabled = this._settings.strategy.isDefaultMultiSelectEnabled;
+      }
+
+      if (isBoolean(settings.strategy.isDefaultSelectCascadeEnabled)) {
+        this._settings.strategy.isDefaultSelectCascadeEnabled = settings.strategy.isDefaultSelectCascadeEnabled;
+        this._strategy.isSelectCascadeEnabled = this._settings.strategy.isDefaultSelectCascadeEnabled;
+      }
     }
 
     // Check if interaction settings are provided
@@ -468,7 +482,9 @@ export class OrbView<N extends INodeBase, E extends IEdgeBase> implements IOrbVi
     const mousePoint = this.getCanvasMousePosition(event);
     const simulationPoint = this._renderer.getSimulationPosition(mousePoint);
 
-    const response = this._strategy.onMouseClick(this._graph, simulationPoint);
+    const response = this._strategy.onMouseClick(this._graph, simulationPoint, {
+      isAppend: event.shiftKey,
+    });
     const subject = response.changedSubject;
 
     if (subject) {