Destiny 2 Guide: Just Starting Out? Read This! Understanding Weapon Range Is the Key to Mastering Combat

The Basics

From storming enemy strongholds to getting ambushed and beyond, the Guardian life is a hectic one.
In this section, I'll be providing you with some veteran Guardian tips to keep you calm and efficient, even in the toughest of situations!
Let's start with the radar. You'll find it sitting in the top left of the screen while exploring. It's an excellent tool that shows the direction hostiles are in, as well as the distance to them.

Viewing the Radar

The direction you are currently facing will always be up on the radar, which is divided into eight sectors.
The radar features three different distance types. If the outer wall of your radar lights up, you'll know the enemy is at long range. If the inner area lights up, it's mid-range. And if the center lights up... Get ready. The enemy's somewhere close by.
In this image, there's a hostile presence at close proximity; dead ahead and to the 2 o'clock position at mid range; as well as to the 11 o'clock position at long range.
Note that enemies in stealth will not show up on your radar, so relying on it 100% of the time is bound to have lethal consequences. 

Use the radar as a reference, while keeping your senses pricked to avoid a deadly flanking. 

I'm Surrounded! What Do I Do?

When you're on the receiving end of an ambush or in the midst of a hectic melee, you may find yourself surrounded on all sides. Maintaining your position will likely end in a gruesome death.
For those Guardians who fancy the prospect of living, retreat is recommended. Scramble behind a structure for shelter or find an area from which to mount your next offensive.

This image depicts the optimal combat situation—one in which enemies appear from a single direction. And should the situation go pear-shaped, there will always be a place to fall back to.
If you don't have the luxury of such an environment, it's recommended you use power weapons and supers to clear weaker foes from the battlefield. Oftentimes, Guardians will be inclined to save the heavy artillery for a boss battle, but remember that survival is always the highest priority.

Recommended Power Level

Each activity comes with a recommended power level. As you might have deduced, the term refers to the recommended power level for an activity's completion.
Enemies also have a recommended power level, which will show upon defeat.
If you feel the foe you're engaging is too strong, there's no need to boulder through to your doom. Retreating, raising your power level, and coming back later is also an effective path to victory.

Range is Everything! Weapon Types and Their Ranges

Once you've mastered the art of traversing without getting flanked, you'll want to begin taking weapon range into account.
Each weapon has an optimal range. Below you'll find a list of basic weapon types and their intended ranges.

Weapons and Their Optimal Ranges:
Sidearms: point-blank range
Submachine Guns: point-blank range
Shotguns: point-blank to close range
Auto Rifles: close to mid range
Hand Cannons: close to mid range
Fusion Rifles: close to mid range
Pulse Rifles: mid range
Scout Rifles: mid to long range
Sniper Rifles: long range
Linear Fusion Rifles: long range

The farther a target is outside of a weapon's ideal range, the less damage will be inflicted. This phenomenon is known as "damage falloff."

When the distance to an enemy is closer than the weapon's optimal range, damage falloff will not occur. However, as gunsight zoom always corresponds to optimal range, using a long-range weapon at close range will prove an unwieldy endeavor.
Also note that optimal range does not apply to grenade launchers, rocket launchers, and swords.
Furthermore, while each weapon category has a broad optimal range (as shown in the above list), the individual weapons within these categories have a more specific optimal range of their own.
For instance, as can be seen in this image, in spite of the two scout rifles belonging to the same category, the range for "Nameless Midnight" differs from that of "Song of Justice VI."
Phrased simply, while scout rifles excel at mid to long-range encounters in a general sense, these two specific scout rifles demonstrate subtle differences within said ranges. Case in point, shots from Song of Justice VI won't succumb to damage falloff for a longer distance than Nameless Midnight.

Conversely, when comparing weapons of different types (and thus different optimal ranges), such as sidearms and scout rifles, a simple side-by-side comparison of stats is not enough to demonstrate the full spectrum of these firearms' usefulness.
Lastly, it's also possible to alter individual weapon stats to some extent, by going into weapon "Details" and swapping out perks.
Try your hand at a variety of weapons until you gain an intuitive grasp of each category's optimal range. Once you've found the range best suited to your play style, assemble an arsenal geared to that range...and master it!
Do that, and foes who previously had you on the run might just become easy pickings.

*Screenshots shown are from the Japanese version. The game is playable in English.