diff --git a/static/js/dom.js b/static/js/dom.js
index b725dff..4339b79 100644
--- a/static/js/dom.js
+++ b/static/js/dom.js
@@ -127,9 +127,20 @@ document.addEventListener("DOMContentLoaded", () => {
         el.addEventListener("click", (ev) => {
             let modal = document.querySelector("#modal");
 
+            let region = ev.target.closest(".node").dataset["name"];
+
             modal.dataset["region"] = ev.target.closest(".node").dataset.name;
             modal.dataset["action"] = "ATTACK";
 
+            let selector = modal.querySelector(".target");
+            selector.replaceChildren("");
+            for (let neighbour of Region.getRegion(region).neighbours) {
+                let opt = document.createElement("option");
+                opt.value = neighbour.name;
+                opt.textContent = neighbour.name;
+                selector.appendChild(opt);
+            }
+
             modal.classList.remove("hidden");
         })
     );
diff --git a/static/js/index.js b/static/js/index.js
index 0b6c4bf..046dab6 100644
--- a/static/js/index.js
+++ b/static/js/index.js
@@ -99,7 +99,7 @@ document.addEventListener("DOMContentLoaded", () => {
                         updateDom();
                     }
                 } else {
-                    if (currentPlayer().act(data)) {
+                    if (await currentPlayer().act(data)) {
                         currentPlayer().endTurn();
                     }
                 }
diff --git a/static/js/player.js b/static/js/player.js
index 6516370..d36d8a0 100644
--- a/static/js/player.js
+++ b/static/js/player.js
@@ -2,6 +2,8 @@ const PHASE_REINFORCE = 1;
 const PHASE_ATTACK = 2;
 const PHASE_FORTIFY = 3;
 
+let totalDice = 0;
+
 class Player {
     constructor(id, name) {
         this.name = name;
@@ -13,6 +15,7 @@ class Player {
         this.isPlaying = false;
         this.reinforcementsPlaced = 0;
         this.reinforcementsAvailable = 0;
+        this.offenderRegion = null;
         this.turnPhase = PHASE_REINFORCE;
 
         this.resetColor();
@@ -81,17 +84,19 @@ class Player {
      * @param data Data received via socket
      * @returns {boolean} Whether this player's turn has ended or not.
      */
-    act(data) {
+    async act(data) {
         console.log(`player: ${this.id}`);
         console.log(data);
 
         if (this.turnPhase === PHASE_REINFORCE) {
-            if (this.reinforce(data)) {
-                this.reinforcementsPlaced += 1;
-            }
+            if (data.region !== undefined) {
+                if (this.reinforce(data)) {
+                    this.reinforcementsPlaced += 1;
+                }
 
-            if (this.reinforcementsPlaced === this.reinforcementsAvailable) {
-                this.turnPhase = PHASE_ATTACK;
+                if (this.reinforcementsPlaced === this.reinforcementsAvailable) {
+                    this.turnPhase = PHASE_ATTACK;
+                }
             }
 
             return false;
@@ -102,10 +107,7 @@ class Player {
             }
 
             if (this.turnPhase === PHASE_ATTACK && data.action === "ATTACK") {
-                if (this.attack(data)) {
-                    this.turnPhase = PHASE_FORTIFY;
-                }
-
+                await this.attack(data);
                 return false;
             }
 
@@ -123,7 +125,76 @@ class Player {
      *
      * @param data Data received via socket
      */
-    attack(data) {}
+    async attack(data) {
+        let offender = Region.getRegion(data.startRegion);
+        let defender = Region.getRegion(data.endRegion);
+        let offenderStrength = parseInt(data.strength);
+        // Assume this for now.
+        let defenderStrength = 1;
+
+        // Basic validation on game state
+        if (
+            offender.owner !== this ||
+            defender.owner === this ||
+            offenderStrength > 3 ||
+            offenderStrength <= 0 ||
+            offenderStrength >= offender.strength ||
+            (this.offenderRegion !== null && this.offenderRegion !== offender)
+        ) {
+            return false;
+        }
+
+        /* How do Risk attacks work?
+        - Offender signs 1-3 armies, defender signs 1-2 armies
+        - Both roll respective dice
+        - Compare pairs of highest die in the rolls to remove armies.
+         */
+
+        if (this.offenderRegion === null) {
+            this.offenderRegion = offender;
+        }
+
+        let offenderRolls = [];
+        let defenderRolls = [];
+
+        // Get random values
+        for (let i = 0; i < offenderStrength; i++) {
+            offenderRolls.push(await random.get(6, `dice-${totalDice}`));
+            totalDice += 1;
+        }
+
+        for (let i = 0; i < defenderStrength; i++) {
+            defenderRolls.push(await random.get(6, `dice-${totalDice}`));
+            totalDice += 1;
+        }
+
+        console.log(`attacker rolls: ${offenderRolls}`);
+        console.log(`defender rolls: ${defenderRolls}`);
+
+        offenderRolls.sort();
+        defenderRolls.sort();
+
+        // Compare and settle.
+        while (offenderRolls.length * defenderRolls.length > 0) {
+            let offenderResult = offenderRolls.pop();
+            let defenderResult = defenderRolls.pop();
+
+            if (offenderResult > defenderResult) {
+                defender.strength -= 1;
+            } else {
+                offender.strength -= 1;
+            }
+
+            if (defender.strength === 0) {
+                defender.strength = offenderRolls.length + 1;
+                offender.strength -= offenderRolls.length + 1;
+                defender.owner = this;
+                break;
+            }
+        }
+
+        updateDom();
+    }
 
     /**
      * Process an action which is to attack another region.
@@ -138,7 +209,8 @@ class Player {
         if (
             sender.owner === this &&
             receiver.owner === this &&
-            sender.strength > strength
+            sender.strength > strength &&
+            strength > 0
         ) {
             receiver.reinforce(strength);
             sender.strength -= strength;
@@ -168,6 +240,7 @@ class Player {
         this.isPlaying = true;
         this.reinforcementsPlaced = 0;
         this.reinforcementsAvailable = this.additionalReinforcements();
+        this.offenderRegion = null;
         this.turnPhase = PHASE_REINFORCE;
     }