PoE 2 Mortar Cannon Persistent Buff Gem Guide

So you've seen the new Strength/Dexterity Persistent Buff Gem pop up in PoE 2 patch notes — Mortar Cannon. At first, I thought it was just another gimmick skill. But after testing it, I can tell you this gem actually changes how grenade builds play. If you've ever been frustrated by grenade cooldowns or clunky manual throws, Mortar Cannon fixes that by dropping a cannon totem that fires your grenades for you.

Here's everything you need to know, broken down in simple, practical steps.

What Mortar Cannon Does

• Type: Strength/Dexterity Persistent Buff Gem
• Effect: Raises a Cannon Totem that automatically uses socketed Grenade Skills
• Bonus: Grants a huge Cooldown Recovery Rate boost, making grenades fire way faster

Think of it as hiring a little helper to do all the grenade tossing while you focus on dodging, DPSing, or stacking more buffs.

Step-by-Step: How to Use Mortar Cannon

Step 1 – Get the Right Grenade Skills

You can't just throw Mortar Cannon into any build. You'll want at least one grenade skill that benefits from faster cooldowns.

• Good options: Incendiary Grenade (fire DoT), Shrapnel Grenade (AoE clear), Frost Grenade (chill/freeze utility).
• Put the grenade skill directly in the same socket setup as Mortar Cannon.

Step 2 – Position Your Cannon Smartly

The cannon is stationary, so placement matters.

1. Drop it at choke points in maps where enemies funnel.
2. Against bosses, place it close enough that grenades always connect but not so close it gets instantly killed.
3. If you're running multiple cannons, stagger them for wide coverage.

Step 3 – Play Around Cooldowns

The real strength here is the cooldown recovery.

• Mortar Cannon throws grenades much faster than you could manually.
• Use that uptime to free yourself for supporting skills: curses, mobility, or extra DPS.
• If you run multiple grenade types, the cannon rotates them smoothly — no downtime.

If you’re excited to try Mortar Cannon but don’t want to grind a fresh character from scratch, the easiest shortcut is to Buy PoE 2 Account online. Starting with a pre-leveled account lets you jump right into grenade builds, test Mortar Cannon at higher levels, and skip the early-game slog so you can enjoy the real explosive fun straight away.

Strengths and Weaknesses

Example Build Idea

If you want to try this out early:

1. Stack Strength gear for cannon durability.
2. Use Incendiary + Shrapnel Grenade as your main sockets.
3. Drop Mortar Cannon at map choke points → run in circles while it bombs everything.
4. Support with a curse (Flammability or Frostbite) to push damage higher.

It feels like playing “tower defense mode” inside PoE 2 — let the cannon do the hard work while you kite and survive.

Recap

Mortar Cannon is more than just a fun gimmick — it's a serious tool for anyone running grenades in PoE 2.

• It summons a Cannon Totem that auto-fires grenades.
• You get crazy cooldown recovery, which fixes grenade downtime.
• Best used for choke-point clearing, boss arenas, and hybrid Strength/Dexterity builds.

If grenades ever felt too clunky or slow for you, Mortar Cannon is the gem that makes them shine. I'm already planning a full grenade build around it — and honestly, watching a cannon endlessly chuck explosives feels ridiculously satisfying.