Gemstone Crab Guide – Best AFK Combat XP in OSRS (2026)

The Gemstone Crab is one of the most hands-off combat training methods in Old School RuneScape, introduced as part of the Varlamore expansion in July 2025. It has no health bar and no defensive stats, and it can’t be killed — you simply attack it and rack up combat experience until it burrows away and relocates every 10 minutes. There’s no food to eat, no prayer to manage, and crucially no way for other players to crash you, since everyone shares the same crab.

That combination makes it ideal for anyone who wants AFK Combat XP. You won’t get the best rates in the game here, but you’ll get 10 minutes of interrupted fighting that only requires 20 clicks per hour.

Unlike most training methods, there’s no single XP-per-hour figure for the Gemstone Crab due to the amount of variance. Your rates depend on everything that affects your DPS:

• Your combat level and the stat you’re training
• Your weapon and gear setup
• Whether you’re using combat potions or boosts
• Your combat style and attack speed

While fighting the Gemstone Crab, you earn 12.5% less experience per hit than normal — 3.5 experience per point of damage instead of the usual 4. Despite that reduction, the crab still tends to beat other commonly trained crabs, for two reasons: there’s far less downtime, and no experience is wasted on overkill. Against a normal monster, rolling a 15 when it only has 1 hitpoint left wastes most of that hit; the Gemstone Crab can’t be killed, so every point of damage you roll counts.

To get an accurate number for your account, train for a measured stretch — say 30 minutes — note your starting and ending XP, and double it. That gives you a real hourly rate for your exact setup, far more reliable than any one-size-fits-all estimate.

• Completion of the Children of the Sun quest (a quick, free-to-start quest in Varrock that takes around 10 minutes)

That’s the only hard requirement. A couple of optional unlocks make getting there much faster:

• Twilight’s Promise — unlocks the Quetzal travel network for the fastest route (see Option 1 below)

Setup here is refreshingly simple: bring your best damage-per-second gear for whichever combat style you’re training, since the Gemstone Crab has no defence and you’re rewarded purely for dealing damage. You won’t need any food, so your inventory can be used for any potions you wish to bring.

⚠️ A word of caution: although unlikely, the Gemstone Crab can deal small amounts of damage, and it is possible to be killed if you’re left at low hitpoints or if you are 1HP Dharoking. Hardcore ironmen especially should keep an eye on their health and bring a little food rather than going in with none.

Since the appeal is long, uninterrupted training, the main thing to optimise for is not running out — carry enough ammo or runes that you won’t have to bank mid-session.

The Gemstone Crab rotates between three possible spawn locations in the Tlati Rainforest. If the crab isn’t at the location you arrive at, just crawl into the cave there and you’ll be taken to the current location.

Option 1: Quetzal (Fastest)

The fastest way to get there is the Quetzal System, which requires the Twilight’s Promise quest. Take the Quetzal from Civitas illa Fortis to Tal Teklan — the furthest-left location on the map. You do not need to build a landing site, as one is already there.

Option 2: Run & Boat (No Twilight’s Promise)

If you haven’t done Twilight’s Promise — and honestly, it’s worth just doing the quest — you can still get there by running from Civitas illa Fortis and taking a boat to Tal Teklan. Once you arrive, the nearest Gemstone Crab location is just north of the boat.

The actual training loop couldn’t be simpler — most of the “strategy” is just getting set up correctly so your sessions run as long as possible.

1. Travel to one of the three mines, or check the caves to find the current spawn.
2. Click the Gemstone Crab to begin attacking — that’s the only action you need to take.
3. Stay in combat for the full 10 minutes with no further interaction required.
4. When the timer ends, the crab burrows and relocates. Re-enter the cave to be taken to its new location.
5. Resume attacking and repeat for as long as you like.

Because the crab can’t be killed and can’t be crashed, there’s no competition for it and no downtime resetting aggression like you’d have at other crab spots — you just follow it from cave to cave.

The Gemstone Crab sits in the same category as classic AFK training spots, so it’s worth knowing where it wins and where it doesn’t.

vs. Sand Crabs: Sand Crabs are free-to-play-adjacent and have no quest requirement, but they come with real downsides — they lose aggression every so often, forcing you to reset by moving out of range, and popular spots get crowded and crashed by other players. The Gemstone Crab fixes both of those: it stays in combat for a clean 10-minute stretch and can’t be crashed, so it’s a noticeably more reliable AFK experience for accounts that have done Children of the Sun.

vs. Nightmare Zone: NMZ can be extremely AFK (up to 6 hours) and has the major advantage of awarding points you can spend on rewards like scroll and ring imbues. The trade-off is setup: NMZ requires a stack of completed quests to unlock good bosses, plus an upkeep of absorption potions and overloads. The Gemstone Crab has none of that overhead — so it’s the easier option when you only care about getting some AFK combat XP.

The bottom line: if you want the lowest-maintenance, lowest-cost AFK combat XP available and don’t need NMZ’s reward economy, the Gemstone Crab is hard to beat. If you specifically want imbues and don’t mind the setup, NMZ still has its place.