OSRS Defence 70-99: Void vs Obsidian NMZ Guide

Game screenshots and facts are cited from the Old School RuneScape Wiki (strategy, equipment, drops, and related pages). Writing is original editorial, not a copy of the wiki article.

Defence is the only combat skill that protects you from every attack style, but training it to 99 is a marathon, not a sprint. Two of the most discussed paths for the 70–99 stretch are Pest Control for Void Knight equipment and AFK obsidian melee at Nightmare Zone. One rewards you with one of the game's most iconic armour sets, while the other is the lazy player's dream—20 minutes of near-zero input at a time.

This guide breaks down requirements, setups, XP rates, gear progression, common mistakes, and the honest time/cost tradeoffs of each method. By the end, you should know exactly which road fits your playstyle, schedule, and bank balance.

Two Roads to 99 Defence

Pest Control is a cooperative minigame where teams defend the Void Knight from an onslaught of monsters. You earn commendation points that can be spent on Void Knight armour or on small XP rewards. Nightmare Zone, on the other hand, is a safe dream-world instance where you fight quest bosses you have already defeated, using absorption potions and auto-retaliate to stay AFK for long stretches.

The core tradeoff is simple: Pest Control gives you gear progression but demands active team play; Nightmare Zone gives you elite AFK rates but only combat XP and points toward imbues. Many players end up doing both—Void for later PvM, NMZ for pure Defence levels. The question is how to weigh them for your current goal.

Who This Is For and Requirements

This comparison is aimed at players who are already 70 Defence and looking at the long grind to 99. It also suits anyone who wants to earn Void while training Defence, or who prefers a low-attention method while working or playing other accounts.

Method 1: AFK Obsidian at Nightmare Zone

Nightmare Zone is the undisputed king of AFK combat training. The obsidian armour set, paired with an obsidian weapon and a berserker necklace, gives a set effect that boosts melee accuracy and damage. That high max hit means better XP rates even when you are not paying attention.

Setup and Inventory

• Gear: full obsidian armour (helmet, platebody, platelegs), obsidian sword (toktz-xil-ak) or obby maul, berserker necklace, a graceful or melee cape slot, and any blessing or ammunition slot that gives a strength bonus.
• Inventory: 4–6 overload potions, 10–14 absorption potions, a rock cake or locator orb to lower HP to 1, and a few super combat potions for when overloads run out or for normal rumble mode.
• Boss list: choose easy melee-only quest bosses like Count Draynor, King Roald, Tree Spirit, Khazard Warlord, Bouncer, and Black Knight Titan. Enable auto-retaliate.

How It Works

Drink an overload, sip an absorption potion to max absorption HP, then use the rock cake or locator orb to drop your real HP to 1. As long as you stay at 1 HP, monsters can only hit your absorption points, never your actual health. Auto-retaliate keeps you attacking, and the obsidian set effect does the damage.

At 70–80 Defence with obsidian and berserker necklace, community reports commonly place the method between 60,000 and 90,000 Defence XP per hour depending on your exact gear, melee stats, and whether you use overloads. That range climbs slightly as your Strength and Attack levels push your max hit higher.

Method 2: Pest Control for Void and Defence XP

Pest Control is a team minigame on the Void Knights' Outpost. Each game lasts a few minutes, and your goal is to protect the Void Knight while destroying four portals. Winning awards commendation points based on the boat: novice gives 1 point, intermediate 2, veteran 3. Points can be exchanged for Void Knight armour or for a small amount of combat XP.

Why Train Defence Here?

The main pull is Void Knight equipment, which has a set effect that boosts accuracy and damage across all combat styles. If you want to eventually do high-level PvM, ranged Void is near-mandatory for some bosses. Training Defence at Pest Control lets you work toward that gear while also gaining melee combat XP from the monsters themselves.

The XP reward from spending points is very small—at level 70 Defence a single point buys only single-digit XP, so the point-to-XP conversion is not a training method on its own. The real Defence XP comes from attacking the monsters with a melee weapon during the minigame. With a good team and a decent weapon, you can expect around 30,000–50,000 melee XP per hour while also banking points, though exact rates depend heavily on team speed and your combat stats.

Point Costs for Void

• Void Knight top: 250 points
• Void Knight bottom: 250 points
• Void Knight gloves: 150 points
• Void Knight melee helm: 200 points
• Void Knight ranged helm: 200 points
• Void Knight mage helm: 200 points

A single full set with one helm costs 850 points. Collecting all three helms raises the total to 1,250 points. At roughly 25–40 games per hour on the veteran boat, that is a significant time investment—but you are also getting Defence XP from combat the entire time.

Gear Comparison: Obsidian vs Void

Both sets have a place, but they serve different purposes. Here is a quick side-by-side.

For pure Defence training at Nightmare Zone, obsidian wins on AFK potential and raw melee XP. Void is a long-term account upgrade that happens to give some Defence XP while you earn it. Many players get Void first because it unlocks better ranged training later, then switch to NMZ for the mindless grind.

XP Rates, Attention, and Time to 99

The total XP from 70 to 99 Defence is 12,296,804. How long that takes depends on your method and how much attention you can give.

The time range for NMZ is wide because your melee stats, gear, and potion choices all move the needle. If you only have 80 Strength and no berserker necklace, expect the lower end. With max Strength, overloads, and optimal bosses, you can push toward 90k or higher. Pest Control's XP/Hour is lower, but you are effectively multi-tasking: training Defence and working on a best-in-slot armour set.

If you plan to use Void for ranged after finishing Defence, check our Ranged 70-99 comparison for how that gear performs at chinchompas or dwarf cannon spots.

Common Mistakes and How to Avoid Them

• Forgetting to lower HP to 1 at NMZ. If your real HP is above 1, monsters can hit through absorption and kill you. Always rock cake or locator orb down before going AFK.
• Choosing the wrong NMZ bosses. Some bosses use magic or ranged attacks that ignore absorption. Stick to the melee-only list.
• Overloads killing your AFK window. Overloads boost damage but expire in 5 minutes. If you want a true 20-minute AFK, use super combat potions instead.
• Pest Control teams that don't defend the Void Knight. If the Knight dies, you get no points. Learn to balance portal damage with defense, or join a coordinated clan chat.
• Cashing in Pest Control points for XP early. Unless you already own all Void pieces you need, save points for gear. The XP reward is negligible.
• Ignoring defence gear for NMZ. While obsidian armour is offensive, you still need decent defence bonuses to survive initial hits before absorption stacks. Don't show up in full strength gear with no defence.

Time vs Cost: Supplies, Points, and Gold

Nightmare Zone has a supply cost: absorption potions, overloads or super combats, and the initial investment in obsidian armour and a berserker necklace. Pest Control is free to play, but its time cost is enormous because XP rates are lower and Void takes hundreds of points.

If you are short on gold to buy obsidian gear or NMZ supplies, buying OSRS gold is an honest shortcut—it lets you skip hours of moneymaking and jump straight into training. View live gold rates to see what the current market looks like.

Pest Control costs nothing in gold, but it demands hours of your active attention. If your real-life schedule is tight, the opportunity cost may outweigh the benefit of earning Void yourself. In that case, buying gold to fund a faster AFK method is the capital-efficient choice; buying a Pest Control boost is the time-efficient choice, but comes with rule-based risk.

Final Verdict and Next Steps

If you need Void Knight armour: do Pest Control until you own the full set, using melee during games to gain Defence XP. Once you have the pieces, switch to Nightmare Zone for the remaining grind to 99.

If you only care about Defence levels: go straight to AFK obsidian at NMZ. The XP per hour is significantly higher and the attention requirement is almost zero. The only downside is you miss out on Void, but you can always go back for it later.

Your next practical step depends on your account:

• Check your Pest Control point balance and current Void pieces to see how close you are.
• Price out obsidian armour, a berserker necklace, and NMZ supplies on the Grand Exchange or from a trusted gold seller.
• Set a realistic weekly XP target and stick to it—70 to 99 is a long runway.

Whichever path you choose, the grind to 99 Defence is one of the most impactful upgrades in Old School RuneScape. Pair it with the right gear and method, and it becomes less of a chore and more of a background task while you live your life.

Sources

• Defence training - OSRS Wiki