Part of the Mechanics Series:

Mechanics Hub: Rally and march rules (Start Here).

How to Level Up Commanders Fast: Forts are a major XP source.

Alliance Guide: You cannot do this alone.

Quick Answer

Barbarian forts can only be attacked by rally — there is no solo option. They are the primary source of Books of Covenant, the material that gates your Castle upgrades and therefore your path to City Hall 25 and T5 troops. Forts run from level 1 to 5 (and higher in some content), every participant is guaranteed resource boxes, experience books and speedups, and your share scales with the damage you deal — so send a full march, not a token one.

Overview

Fort rallies are the most reliably underrated daily activity in Rise of Kingdoms. New players skip them because the rewards look modest on a single run. What they miss is that forts are the main tap for Books of Covenant, and Books of Covenant are what stand between you and Castle 25 — which is a hard prerequisite for the whole T5 project.

An alliance that runs forts consistently for a year arrives at the T5 gate with the books already banked. One that does not, does not.

How Fort Rallies Work

Rally only. You cannot solo a fort. Someone starts the rally, others join inside the preparation window, and the combined force attacks as one — see the rally vs garrison explanation.
The rally leader's commanders apply to the whole force, which is why the strongest fort commander in the alliance should be leading, not joining.
Fort levels 1–5 cover the standard range. Levels 1–3 are comfortable for a developing alliance; 4 and above want better research and properly built commanders.
Everyone who participates gets paid. There is no "too small to bother joining" — participation is the requirement.

The Rewards

Every participant in a fort rally is guaranteed:

Resource boxes
Experience books — a serious chunk of your commander XP economy
Speedups

...with quantities scaling by fort level and by how much damage you personally dealt.

On top of that sits the reason you are really here:

Books of Covenant, with roughly a 50% chance at each reward tier. A single level 5 fort rally typically yields somewhere in the region of 5 to 15 books across the run.

Why Damage Matters

Your reward share is driven by total damage dealt, and this has a direct practical consequence: send your full march, with your best fort pair, every time.

Joining a fort rally with a half-filled march because you are saving troops is a false economy. Fort fights do not cost you meaningfully in permanent losses the way player combat does, and the reward difference between a full march and a token one is large.

Best Commanders for Forts

You want three things: nuke damage, peacekeeping talents, and bonus damage to barbarians. The commonly recommended fort commanders are:

Boudica
Aethelflaed
Cao Cao
Minamoto no Yoshitsune
Belisarius

All five combine burst damage with peacekeeping-tree access, which is exactly the profile forts reward. Build the Peacekeeping tree on whichever of them you own — see the talent trees guide — and note that the same pair doing your daily barbarian clearing is the pair you want here.

Books of Covenant: What They Are For

Books of Covenant feed Castle upgrades, and the Castle is one of the sixteen buildings that must reach level 25 before City Hall 25 unlocks. It is the classic bottleneck of the entire T5 project — thousands of books, obtainable at a few per fort rally.

The arithmetic is unforgiving and it explains a lot about why some accounts reach T5 a season ahead of others. There is no way to rush it late. You either joined fort rallies for months or you did not.

Fitting Forts Into Your Day

Join every fort rally your alliance calls. This is the single highest-value habit available to a mid-game account.
Ask your alliance to schedule them at fixed times. Predictability is what gets attendance.
Spend action points on barbarians between forts — see how to level up commanders fast. During Lohar's Trial that same clearing also farms event rewards, so bank action points before the window.
Lead rallies yourself once your fort pair is genuinely the alliance's best. Leader commanders apply to everyone, so the strongest pair in the lead slot lifts the whole alliance's rewards.

FAQ

Can you solo a barbarian fort in Rise of Kingdoms?

No. Forts are rally-only, which makes an active alliance a hard requirement for farming them.

What do barbarian forts drop?

Resource boxes, experience books and speedups for every participant, plus Books of Covenant at roughly a 50% chance per reward tier.

How many Books of Covenant does a level 5 fort give?

Typically around 5 to 15 per rally, depending on damage dealt and reward tiers hit.

What are Books of Covenant used for?

Castle upgrades — and Castle 25 is a prerequisite for City Hall 25 and therefore for T5 troops.

Which commanders are best for barbarian forts?

Boudica, Aethelflaed, Cao Cao, Minamoto and Belisarius — nuke damage plus peacekeeping talents plus bonus damage to barbarians.

Should I join a fort rally with a small march?

Join, but fill the march. Rewards scale with damage dealt, so a full march is worth substantially more than a token one.

Key Takeaways

Forts are rally-only. No alliance, no forts, no books.
Rewards scale with your damage — always send a full march.
Books of Covenant gate Castle 25, which gates City Hall 25 and T5.
Boudica, Aethelflaed, Cao Cao, Minamoto and Belisarius are the fort staples.
The rally leader's commanders apply to everyone. Put the best pair in the lead slot.

Rise of Kingdoms Barbarian Forts: Rallies, Levels and Books of Covenant