The Rate of Fire, or ROF is the determinant of the speed at which a unit or building attacks. It is a measurement of time between two attacks. A unit with an ROF of 3 will attack every 3 seconds. The lower the Rate of Fire, the faster it attacks. Thus, a lower Rate of Fire is better.
Age of Empires 
Edit
Most infantry and cavalry units in the game have a fast ROF, as well as the Scout Ship line and the Helepolis. The Stone Thrower line, on the other hand has slow ROF, and so does the Catapult Trireme and the Juggernaught, whereas the Ballista has medium ROF.
The unit with the fastest ROF is the Fire Galley, which coupled with its large attack, means that it can easily fell ships in groups.
These civilizations have bonuses related to ROF:
- Assyrians: (+25% Archery Range unit fire rate)
- Persians: (Trireme +25% fire rate)
- Phoenicians: +30% Catapult Trireme and Juggernaught fire rate
- Sumerians: +50% Stone Thrower, Catapult, and Heavy Catapult fire rate
- Romans: Swordsmen attack +33% faster
Age of Empires II Edit
In Age of Empires II, the most common ROF is 2.03. There are some units with a faster attack; most notably the Fire Ship with a ROF of 0.25, which is by far the fastest attack. Quite a few units have a slower attack, though. Units with heavy attack, such as siege weapons and gunpowder units have a much higher ROF, and most trash units and mounted archers also attack at a lower speed. Lastly, naval vessels (bar the Fire Ship) range below the standard value. Listed below are all units and buildings in Age of Empires II that have a ROF different from 2.03.
| Unit/Building | Base Rate of Fire |
|---|---|
| Fire Galley line | 0.25 |
| Elite Cataphract | 1.73 |
| Knight, Cavalier, Cataphract, (Elite) Magyar Huszar | 1.83 |
| Hussar, Paladin, (Elite) Samurai, (Elite) Plumed Archer, Condottiero, (Elite) Boyar | 1.93 |
| (Elite) Mangudai, (Elite) Tarkan | 2.13 |
| (Elite) War Wagon, (Elite) Elephant Archer, (Elite) Ballista Elephant | 2.5 |
| (Elite) Conquistador | 2.93 |
| Spearman line, Skirmisher line, Genoese Crossbowman, (Elite) Genitour, Galley line, (Elite) Caravel, Harbor | 3.05 |
| (Elite) Longboat | 3.34 |
| (Elite) Organ Gun | 3.45 |
| Hand Cannoneer, (Elite) Janissary | 3.49 |
| (Heavy) Scorpion | 3.6 |
| Chu Ko Nu | 3.65 |
| Elite Chu Ko Nu | 3.84 |
| Ram line | 5.0 |
| Mangonel line, (Elite) Turtle Ship, Bombard Tower | 6.0 |
| Bombard Cannon | 6.5 |
| Trebuchet, (Elite) Cannon Galleon | 10.0 |
Age of Mythology Edit
The Rate of Fire also plays a role in Age of Mythology but is instead divided into two factors: Rate and AnimationRate. In a unit's anim.txt file, all units have a rate of 5, however it is unknown whether or not this truly affects a units Rate of Fire. Otherwise the Rate of Fire is dependent on the AnimationRate (which is normally defined in the unit's model files), and can theoretically be affected by technologies (although such technologies do not exist in the base game or its expansions).
Age of Empires IIIEdit
Almost all civilizations' ranged units (such as Musketeers, Crossbowmen, and Dragoons) have a standard ROF of 3 for their ranged attacks, regardless of their weapon. Siege attacks are also generally fired at a ROF of 3. All melee attacks have an ROF of 1.5. Cannons' ROF are normally in the ballpark of 4-6.
The main exceptions are ranged cavalry with a bow, such as the Bow Rider and Cavalry Archer, which have an ROF of 1.5, and Mercenaries/Outlaws, which vary from 1.5 to 4.0. For artillery, the Chinese Flamethrower is a very special case, having an ROF of 0.5 (essentially firing continuously), while the Great Bombard has a ROF of 8.
