The Morph-Gun is Jak's major line of offense from Jak II onwards. There are multiple modifications that can be made to the Morph Gun, which give it different firepower capabilities. In Jak 3, each mod can also be upgraded twice for increasingly devastating results.
It uses different mods, each one based on a source of Eco, having properties based on this source of energy: the Red Mod is used for strong close range weapons; the yellow mod is used for precision at long range; the blue mod is used for speed and firerate; and the Dark Mod is used for weapons of mass destruction, that are powerful and can kill with one shot.
The Red Mod is most notable for its power. It is stronger than both the Yellow Mod and the Blue Mod, but lacks in range. It is mostly aimed at taking down lots of enemies in specific situations. It's a good 'crowd weapon', mainly for head on attacks when foes are dangerously close. But with skilled players, it would probably be your last choice. Unless you have skill in its 3rd stage (Jak 3) at launching its charge into enemy 'tight-spots'.
The Yellow Mod is most notable for its blend of power and range. With the laser sight it can target enemies from far away and effectively take them out in a few hits. Though it doesn't pack as much punch as the other Mods, it is a decent choice for beginners and Masters. Each of the mods are useful in different situations, but the Yellow Mod is a good all-around weapon for almost any situation.
Upgrade 1 and 2 of the Yellow Mod are most effective when used with the rapid fire technique especially with upgrade 2 because it takes out enemies from far and near and all around.
The Blue Mod is most notable for its speed. The rapid bullets make cake of most enemies. It serves very well in short ranged battles. Though not a good one to always take with you, as it chews through ammo, it is a fine alternative to get through areas where the enemies are a little too persistent. It works great to stream through enemy forces with the constant amount of damage it outputs. It's faster than the Blaster(Yellow Mod) but does less damage.
The Dark Mod is the strongest and most powerful of all the Mods. It is perfect for slaughtering enemies when they are grouped together. These mods have to be used sparingly, as they tend to have few shots and a slow rate of fire. In any case, it is perfect for those grouped together or taking down a lot of enemies at once. It's ammo is powered by Dark Eco, the same eco used in Dark Jak's most powerful Moves. Unfortunately ammunition is scarce as it drains fast, and can't be replenished in large amounts (unless secrets unlocked).
Other Morph Gun Upgrades
In Jak 2, there are 3 gun upgrades that adjust the performance of all the mods. These are: the Scatter Gun Rate-of-Fire Upgrade (makes the Scatter Gun fire much faster), the Ammunition Capacity upgrade (increases how much ammo the guns can carry), and the Damage Upgrade (makes all of the mods much more powerful).
In Jak 3, gun upgrades are bought with Precursor Orbs. As well as some of the old upgrades, there are also Ammunition Consumption upgrades for the Needle Lazer, Plasmite RPG and Super Nova, Increased Duration upgrades for the Gyro Burster and Mass Inverter, and the Robot Shock upgrade for the Arc Wielder.
- In fact, these guns were created to replace Eco from the first game. The Red mod is powerful in an area of effect, like Red Eco. Yellow Eco attacks from a distance like the Yellow Mod. Blue Mods shoot fast like Blue Eco. Dark Eco is just incredibly powerful, like the Dark or Purple Mod.
- The actual Morph Gun can be seen via a glitch in Jak 3, first, equip any weapon then switch it out while crouching(moving) and holding the same button, Jak will put the gun mod away and switch to the "original" morph gun, it is notably smaller and floats in Jak's hands. This trick can also be done in Jak 2, but you have switch out while rolling, though here he isn't holding anything.