diff --git a/src/game/combat/actions.ts b/src/game/combat/actions.ts
index 9ca22d4..1ef6931 100644
--- a/src/game/combat/actions.ts
+++ b/src/game/combat/actions.ts
@@ -1,4 +1,4 @@
-import { StatTest, StatVigorTest, StatVigorSizeTest, OpposedStatTest, TestCategory } from './tests'
+import { StatTest, StatVigorTest, StatVigorSizeTest, OpposedStatTest, TestCategory, CompositionTest, OpposedStatScorer } from './tests'
 import { DynText, LiveText, TextLike, Verb, PairLine, PairLineArgs } from '../language'
 import { Entity } from '../entity'
 import { Creature } from "../creature"
@@ -67,13 +67,23 @@ export class AttackAction extends DamageAction {
       verb.root.capital,
       'Attack the enemy',
       damage,
-      [new StatTest(
-        Stat.Power,
-        15,
-        (user, target) => new LogLine(
-          `${user.name.capital} ${user.name.conjugate(new Verb('miss', 'misses'))} ${target.name.objective}!`
+      [
+        new CompositionTest(
+          [
+            new OpposedStatScorer(
+              {
+                Power: 1
+              },
+              {
+                Reflexes: 1
+              }
+            )
+          ],
+          (user, target) => new LogLine(`${user.name.capital} ${user.name.conjugate(new Verb("swing"))} and ${user.name.conjugate(new Verb("miss", "misses"))} ${target.name.objective}.`),
+          TestCategory.Attack,
+          0
         )
-      )],
+      ],
       [new TogetherCondition()]
     )
   }
diff --git a/src/game/combat/tests.ts b/src/game/combat/tests.ts
index d76e470..995c0de 100644
--- a/src/game/combat/tests.ts
+++ b/src/game/combat/tests.ts
@@ -9,6 +9,88 @@ function logistic (x0: number, L: number, k: number): (x: number) => number {
   }
 }
 
+/**
+ * A [[Scorer]] produces a score for a creature in a certain situation
+ */
+export interface Scorer {
+  userScore (attacker: Creature): number;
+  targetScore (defender: Creature): number;
+  explain(user: Creature, target: Creature): LogEntry;
+}
+
+export class OpposedStatScorer implements Scorer {
+  private maxStatVigorPenalty = 0.5
+  private maxTotalVigorPenalty = 0.1
+
+  constructor (private userStats: Partial<Stats & VoreStats>, private targetStats: Partial<Stats & VoreStats>) {
+
+  }
+
+  explain (user: Creature, target: Creature): LogEntry {
+    return new LogLines(
+      new LogLine(
+        `Pits `,
+        ...Object.entries(this.userStats).map(([stat, frac]) => {
+          if (frac !== undefined) {
+            return new LogLine(`${(frac * 100).toFixed(0)}% `, new PropElem(stat as Stat))
+          } else {
+            return nilLog
+          }
+        }),
+        ` against `,
+        ...Object.entries(this.targetStats).map(([stat, frac]) => {
+          if (frac !== undefined) {
+            return new LogLine(`${(frac * 100).toFixed(0)}% `, new PropElem(stat as Stat))
+          } else {
+            return nilLog
+          }
+        })
+      ),
+      new LogLine(
+        `Score delta: ${this.computeScore(user, this.userStats) - this.computeScore(target, this.targetStats)}`
+      )
+    )
+  }
+
+  userScore (attacker: Creature): number {
+    return this.computeScore(attacker, this.userStats)
+  }
+
+  targetScore (defender: Creature): number {
+    return this.computeScore(defender, this.targetStats)
+  }
+
+  private computeScore (subject: Creature, parts: Partial<Stats & VoreStats>): number {
+    const total = Object.entries(parts).reduce((total: number, [stat, frac]) => {
+      if (stat in Stat) {
+        let value = subject.stats[stat as Stat] * (frac === undefined ? 0 : frac)
+
+        const vigor = StatToVigor[stat as Stat]
+        value = value * (1 - this.maxStatVigorPenalty) + value * this.maxStatVigorPenalty * subject.vigors[vigor] / subject.maxVigors[vigor]
+
+        return total + value
+      } else if (stat in VoreStat) {
+        const value = subject.voreStats[stat as VoreStat] * (frac === undefined ? 0 : frac)
+
+        return total + value
+      } else {
+        return total
+      }
+    }, 0)
+
+    const modifiedTotal = Object.keys(Vigor).reduce(
+      (total, vigor) => {
+        const base = total * (1 - this.maxTotalVigorPenalty)
+        const modified = total * this.maxTotalVigorPenalty * subject.vigors[vigor as Vigor] / subject.maxVigors[vigor as Vigor]
+        return base + modified
+      },
+      total
+    )
+
+    return modifiedTotal
+  }
+}
+
 // TODO this will need to be able to return a LogEntry at some point
 
 abstract class RandomTest implements CombatTest {
@@ -38,6 +120,37 @@ export enum TestCategory {
   Vore = "Vore"
 }
 
+export class CompositionTest extends RandomTest {
+  private f: (x: number) => number
+  private k = 0.1
+
+  constructor (
+    private scorers: Scorer[],
+    fail: (user: Creature, target: Creature) => LogEntry,
+    public category: TestCategory,
+    private bias = 0
+  ) {
+    super(fail)
+    this.f = logistic(0, 1, this.k)
+  }
+
+  explain (user: Creature, target: Creature): LogEntry {
+    return new LogLines(
+      ...this.scorers.map(scorer => scorer.explain(user, target))
+    )
+  }
+
+  odds (user: Creature, target: Creature): number {
+    const userScore = this.scorers.reduce((score, scorer) => score + scorer.userScore(user), 0)
+    const targetScore = this.scorers.reduce((score, scorer) => score + scorer.targetScore(target), 0)
+
+    const userMod = user.effects.reduce((score, effect) => score + effect.modTestOffense(user, target, this.category), 0)
+    const targetMod = target.effects.reduce((score, effect) => score + effect.modTestDefense(target, user, this.category), 0)
+
+    return this.f(userScore - targetScore + this.bias)
+  }
+}
+
 export class OpposedStatTest extends RandomTest {
   private f: (x: number) => number
   private k = 0.1