diff --git a/TODO.md b/TODO.md
index 9d1cc5e..6e42105 100644
--- a/TODO.md
+++ b/TODO.md
@@ -4,6 +4,14 @@ Backlog of bugs + long-term items. Milestones live in REWORK_PLAN.md.
 
 ## Open
 
+### REview undo/redo around death stuff. doesnt work.
+suspect not writing to undo log?
+
+### bug - start/end/resume combat should not be in undo I think...
+
+## dying>stabe state - add +1hp in 1d4 hours DISPLAY (maybe show a rolled hours too) for while stable
+
+## dying>stabe state - add +1hp in 1d4 hours DISPLAY (maybe show a rolled hours too) for while stable
 ### FEAT: critical damage button for dying/stable participants
 - Shared logic already supports `applyHpChange(..., { isCriticalHit:true })`.
 - UI only has normal Damage, which adds 1 failure at 0 HP.
@@ -13,15 +21,11 @@ Backlog of bugs + long-term items. Milestones live in REWORK_PLAN.md.
 
 ### dm list - keep active particpant in view (scroll)
 
+### combat.js doesnt seem to actually exercise the add characters.  there are no characters in the campaign.   only in the encounter..
 
 #### debug feature - button to delet all campaigns - only in dev builds
 
-### bug - start/end/resume combat should not be in undo I think...
 
-### combat.js doesnt seem to actually exercise the add characters.  there are no characters in the campaign.   only in the encounter..
-
-
-## dying>stabe state - add +1hp in 1d4 hours DISPLAY (maybe show a rolled hours too) for while stable
 
 ### FEAT: player display fade transitions for inactive state
 - Inactive is DM-triggered via Mark Inactive.
diff --git a/scripts/combat/replay.js b/scripts/combat/replay.js
index 41a6a85..255feb7 100644
--- a/scripts/combat/replay.js
+++ b/scripts/combat/replay.js
@@ -16,6 +16,7 @@ const {
   startEncounter, nextTurn, togglePause, endEncounter,
   addParticipant, updateParticipant, removeParticipant,
   toggleParticipantActive, applyHpChange, deathSave,
+  stabilizeParticipant, reviveParticipant,
   toggleCondition, reorderParticipants,
 } = shared;
 const { createServerStorage } = require('../../src/storage/server');
@@ -51,7 +52,7 @@ function buildMonsters() {
     { name: 'Goblin2', maxHp: 30, initMod: 2 },
     { name: 'OrcBoss', maxHp: 120, initMod: 1 },
     { name: 'Wolf', maxHp: 40, initMod: 3 },
-    { name: 'Merchant', maxHp: 30, initMod: 0, isNpc: true },
+    { name: 'Merchant', maxHp: 30, initMod: 0, asNpc: true },
   ];
 }
 
@@ -221,7 +222,7 @@ module.exports = async function replay(args) {
           : `${a.target} took ${a.amount} damage`;
       case 'toggleCondition': return `${a.participant} ${a.condition} toggled`;
       case 'updateParticipant': return `${a.participant} edited`;
-      case 'deathSave': return `${a.participant} death save (${a.type})`;
+      case 'deathSave': return `${a.participant} death save (${a.outcome})`;
       case 'toggleParticipantActive':
         return a.revive ? `${a.participant} reactivated` : `${a.participant} toggled`;
       case 'togglePause': return a.to === 'paused' ? 'Combat paused' : 'Combat resumed';
@@ -301,11 +302,14 @@ module.exports = async function replay(args) {
           (e) => updateParticipant(e, actor.id, { notes: `edited r${enc.round}` }, ctx))).enc;
       }
 
-      if (actor.status === 'dying' && !actor.isNpc) {
-        if (VERBOSE) console.log(`    deathSave ${actor.name} +1 success`);
-        enc = (await callStep('deathSave',
-          { participant: actor.name, outcome: 'success' },
-          (e) => deathSave(e, actor.id, 'success', ctx))).enc;
+      if (actor.status === 'dying' && (actor.type === 'character' || actor.type === 'npc')) {
+        const outcomes = ['success', 'fail', 'nat1', 'nat20'];
+        const outcome = outcomes[totalTurns % outcomes.length];
+        if (VERBOSE) console.log(`    deathSave ${actor.name} ${outcome}`);
+        const dsRes = await callStep('deathSave',
+          { participant: actor.name, outcome },
+          async (e) => (await deathSave(e, actor.id, outcome, ctx)).enc);
+        enc = dsRes.enc;
       }
 
       if (totalTurns % 9 === 0) {
@@ -376,19 +380,28 @@ module.exports = async function replay(args) {
       }
       console.log(`--- round ${enc.round} ---`);
       lastRound = enc.round;
-      const dead = enc.participants.filter(p => p.currentHp <= 0 || p.isActive === false);
-      for (const d of dead) {
+      const down = enc.participants.filter(p => p.currentHp <= 0 || p.isActive === false);
+      for (const d of down) {
         if (interrupted) break;
-        if (d.isActive === false) {
-          if (VERBOSE) console.log(`  revive ${d.name}`);
-          enc = (await callStep('toggleParticipantActive',
+        if (d.status === 'dead') {
+          if (VERBOSE) console.log(`  revive dead ${d.name}`);
+          enc = (await callStep('reviveParticipant',
             { participant: d.name, revive: true },
-            (e) => toggleParticipantActive(e, d.id, ctx))).enc;
+            (e) => reviveParticipant(e, d.id, ctx))).enc;
+        }
+        if (d.status === 'stable') {
+          if (VERBOSE) console.log(`  heal stable ${d.name} +${d.maxHp}`);
+          enc = (await callStep('applyHpChange',
+            { target: d.name, changeType: 'heal', amount: d.maxHp, revive: true },
+            (e) => applyHpChange(e, d.id, 'heal', d.maxHp, ctx))).enc;
+        }
+        const latest = (enc.participants || []).find(p => p.id === d.id);
+        if (latest && latest.isActive === false) {
+          if (VERBOSE) console.log(`  reactivate ${latest.name}`);
+          enc = (await callStep('toggleParticipantActive',
+            { participant: latest.name, revive: true },
+            (e) => toggleParticipantActive(e, latest.id, ctx))).enc;
         }
-        if (VERBOSE) console.log(`  heal ${d.name} +${d.maxHp}`);
-        enc = (await callStep('applyHpChange',
-          { target: d.name, changeType: 'heal', amount: d.maxHp, revive: true },
-          (e) => applyHpChange(e, d.id, 'heal', d.maxHp, ctx))).enc;
       }
     }
 
diff --git a/src/tests/Combat.scenario.test.js b/src/tests/Combat.scenario.test.js
index ab491a7..db7fe76 100644
--- a/src/tests/Combat.scenario.test.js
+++ b/src/tests/Combat.scenario.test.js
@@ -27,6 +27,8 @@ const {
   toggleParticipantActive: combatToggleActive,
   applyHpChange: combatApplyHpChange,
   deathSave: combatDeathSave,
+  stabilizeParticipant,
+  reviveParticipant,
   toggleCondition: combatToggleCondition,
   reorderParticipants,
 } = require('../../shared');
@@ -110,10 +112,12 @@ async function nextTurnAction() { enc = await nextTurn(enc, ctx); }
 async function pauseCombat() { enc = await togglePause(enc, ctx); if (!enc.isPaused) throw new Error('not paused'); }
 async function resumeCombat() { enc = await togglePause(enc, ctx); if (enc.isPaused) throw new Error('not resumed'); }
 
-async function applyDamage(name, amount) {
+async function applyDamage(name, amount, options = null) {
   const p = any(name);
-  if (!p || p.currentHp <= 0) return;
-  enc = await combatApplyHpChange(enc, p.id, 'damage', amount, ctx);
+  if (!p || (p.currentHp <= 0 && p.status === 'dead')) return;
+  enc = options
+    ? await combatApplyHpChange(enc, p.id, 'damage', amount, options, ctx)
+    : await combatApplyHpChange(enc, p.id, 'damage', amount, ctx);
 }
 async function applyHeal(name, amount) {
   const p = any(name);
@@ -146,6 +150,16 @@ async function deathSaveAction(name, outcome) {
   const r = await combatDeathSave(enc, p.id, outcome, ctx);
   enc = r.enc;
 }
+async function stabilizeAction(name) {
+  const p = any(name);
+  if (!p) throw new Error(`no stabilize target: ${name}`);
+  enc = await stabilizeParticipant(enc, p.id, ctx);
+}
+async function reviveAction(name) {
+  const p = any(name);
+  if (!p) throw new Error(`no revive target: ${name}`);
+  enc = await reviveParticipant(enc, p.id, ctx);
+}
 async function dragTie(draggedName, targetName) {
   const d = any(draggedName), t = any(targetName);
   if (!d || !t) throw new Error('drag target missing');
@@ -170,6 +184,72 @@ beforeEach(() => {
   RESULTS.length = 0;
 });
 
+test('death-save edge cases in combat scenario helpers', async () => {
+  await record('addChar Fighter', () => addCharacterViaUI('Fighter', 30, 2));
+  await record('addChar Cleric', () => addCharacterViaUI('Cleric', 24, 1));
+  await record('addAllChars', () => addAllCharacters());
+  await record('addMonster Goblin', () => addMonsterParticipant('Goblin', 8, 2));
+  await record('addNpc Merchant', () => addMonsterParticipant('Merchant', 12, 0, true));
+  await record('startCombat', () => startCombat());
+
+  await record('monster drops dead inactive', async () => {
+    await applyDamage('Goblin', any('Goblin').currentHp);
+    const g = any('Goblin');
+    expect(g.status).toBe('dead');
+    expect(g.isActive).toBe(false);
+  });
+
+  await record('npc nat20 returns conscious', async () => {
+    await applyDamage('Merchant', any('Merchant').currentHp);
+    expect(any('Merchant').status).toBe('dying');
+    await deathSaveAction('Merchant', 'nat20');
+    expect(any('Merchant').status).toBe('conscious');
+    expect(any('Merchant').currentHp).toBe(1);
+  });
+
+  await record('npc nat1 plus damage kills, revive/heal restores', async () => {
+    await applyDamage('Merchant', any('Merchant').currentHp);
+    await deathSaveAction('Merchant', 'nat1');
+    expect(any('Merchant').deathSaveFailures).toBe(2);
+    await applyDamage('Merchant', 1);
+    expect(any('Merchant').status).toBe('dead');
+    expect(any('Merchant').isActive).toBe(true);
+    await reviveAction('Merchant');
+    expect(any('Merchant').status).toBe('stable');
+    await applyHeal('Merchant', 5);
+    expect(any('Merchant').status).toBe('conscious');
+    expect(any('Merchant').currentHp).toBe(5);
+  });
+
+  await record('character stable then crit damage dies', async () => {
+    await applyDamage('Fighter', any('Fighter').currentHp);
+    await deathSaveAction('Fighter', 'success');
+    await deathSaveAction('Fighter', 'success');
+    await deathSaveAction('Fighter', 'success');
+    expect(any('Fighter').status).toBe('stable');
+    await applyDamage('Fighter', 1);
+    expect(any('Fighter').status).toBe('dying');
+    expect(any('Fighter').deathSaveFailures).toBe(1);
+    await applyDamage('Fighter', 1, { isCriticalHit: true });
+    expect(any('Fighter').status).toBe('dead');
+    expect(any('Fighter').isActive).toBe(true);
+  });
+
+  await record('massive damage kills character but does not deactivate', async () => {
+    await applyDamage('Cleric', any('Cleric').currentHp + any('Cleric').maxHp);
+    expect(any('Cleric').status).toBe('dead');
+    expect(any('Cleric').isActive).toBe(true);
+  });
+
+  const failed = RESULTS.filter(x => !x.ok);
+  if (failed.length > 0) {
+    const msg = failed.map(f => `FAIL [${f.phase}]: ${f.err}`).join('\n');
+    // eslint-disable-next-line no-console
+    console.error(`\n=== SCENARIO FAILURES (${failed.length}/${RESULTS.length}) ===\n${msg}\n`);
+  }
+  expect(failed).toEqual([]);
+});
+
 test('full 100-round combat scenario (shared, no React)', async () => {
   await record('addChar Fighter', () => addCharacterViaUI('Fighter', 30, 2));
   await record('addChar Cleric', () => addCharacterViaUI('Cleric', 24, 1));
@@ -182,9 +262,7 @@ test('full 100-round combat scenario (shared, no React)', async () => {
   await record('addNpc Merchant', () => addMonsterParticipant('Merchant', 12, 0, true));
 
   await record('addCharParticipant Fighter', () => addCharacterParticipant('Fighter'));
-  await record('addCharParticipant Cleric', () => addCharacterParticipant('Cleric'));
-  await record('addCharParticipant Rogue', () => addCharacterParticipant('Rogue'));
-  await record('addAllChars', () => addAllCharacters());
+  await record('addAllChars Cleric/Rogue', () => addAllCharacters());
 
   await record('toggleHidePlayerHp', () => toggleHidePlayerHpAction());
   await record('toggleHidePlayerHp back', () => toggleHidePlayerHpAction());