My good friend Paul is about to start playing Destiny with me on the ps4, so I figured I should explain to him the game mechanics upfront so he can make wise decisions early on and maximize his playing time. And since it's me I figured I might as well share my notes publicly. Do realize this focuses on the game mechanics and not explaining every minute detail of the game, so I will gloss over some bits.

Until you're level 20

Destiny's game mechanics are very different from when you start a character until you hit level 20 compared to level 20 and beyond (currently the level cap is 30).

Leveling up

Until level 20 you level up your character through experience; standard fare compared to other games.

Focuses

Beyond simply having a level, your character also has a focus. You start with one focus and unlock new abilities of your focus through experience. Once you hit level 15, though, you unlock a second focus that you can switch to. Now when you switch your new focus will have no abilities, so that means e.g. no grenades initially.

By the time you hit level 15 you will probably want to have decided if you want to stick with your initial focus or switch and start building up your new focus. Getting deep into your abilities takes a lot of time so you probably don't want to go too far into any one focus that you don't think you will care about.

I should also note that the level 15 unlock is only required for one character. After that any new character you start will be able to switch focuses from the beginning.

Reputation

Once you hit level 4 you unlock bounties. You complete bounties for reputation which you will care about once you are past level 20, so start completing bounties as soon as you can. Reputation is essentially a ranking amongst various factions in Destiny which sell different gear. For any faction, rank 1 lets you buy pretty stuff, rank 2 is armour, and rank 3 is weapons. When you start a character you earn reputation for the Vanguard for any non-PvP bounties, patrols, and strikes. Playing in the Crucible -- which is the PvP multiplayer -- earns you Crucible reputation. You can't buy any gear from a faction until you hit level 18, but you can at least earn reputation starting at level 4.

At level 18 you start earning marks which is the currency of the factions. You can get Vanguard marks for completing various kinds of strikes. Crucible marks come from playing in the Crucible.

One thing to realize about turning in bounties is that the reputation is not only for you but the items you have equipped. This means if you have maxed out an item you can swap in another one you use on occasion, turn in a bounty, and then have the item gain experience without ever using it to earn that bounty.

Items

Initially you get items either through buying them using glimmer (the basic currency which is shared amongst your characters), drops from enemies, or rewards for completing things such as missions.

The rarity of items is:
0. Common -- white
0. Uncommon -- green
0. Rare -- blue
0. Legendary -- purple
0. Exotic -- gold

Until you hit level 20 you will only get common and uncommon items.

Starting with uncommon items, you can level up your items through experience and materials. The basics just use glimmer to unlock item abilities, but later on harder-to-obtain materials are necessary. Basically anything that takes glimmer and/or weapons parts you can just upgrade without caring. All other upgrades should be thought through based on how much you like the item.

You can share items between your characters through the vault in the Tower. You should also realize that all drops you pick up in the game are unique to you, so there is no arguing over who gets what loot.

Level 20 and beyond

Items

Once you hit level 20 you still start earning rare items. You also begin to see legendary items as well as working towards exotic gear.

Exotic items

Exotic items are extremely quirky compared to the other item rarities. To begin with, you can only have a single exotic weapon and a single piece of exotic armor equipped at one time.

How you obtain exotic items is also quirky. You can collect motes of light which you take to the Watcher for exotic gear. You can collect Strange Coins to trade with Xur (who only shows up on weekends). You can get exotic bounties with some ridiculous requirements. Or you can complete raids.

Factions

Remember how you have been earning reputation for the Vanguard and Crucible since you hit level 4? Well now you have a bunch of factions to earn for. There are 3 other core factions always in the Tower along with unique ones that rotate in every so often for a limited time. If you wear a trinket from a faction then all of your reputation, Vanguard or Crucible, works toward your reputation for that faction (this only applies to the non-default factions, i.e. not Vanguard and Crucible). You will use only Crucible marks to buy items, though, with these other factions. They all have different focuses in terms of stats so that will influence what faction you focus on.

What all this means is that if you play both PvP and PvE then you may want to choose a non-default faction so as to pool your experience. It does mean, though, you will need to play enough multiplayer to earn the Crucible marks required to purchase items.

Leveling up

One of the biggest shifts in Destiny once you hit level 20 is that you level up not through experience but light. Rare armour and higher have an amount of light and the total light amount decides what level you are at. You can get to level 24 on rare items alone and level 28 with bought legendary items. But to hit past level 28 you will need to either earn higher end legendary gear or get an exotic piece of armour.

Summary

• Start doing bounties as soon as you can
• Choose a focus at level 15 and plan to stick with it
• Leveling up item abilities that only cost glimmer and/or weapon parts should just be done, other materials should be watched after
• At level 20 decide if you want to earn reputation with a specific faction
• If you have already played a character previously then know that the new characters share the vault, glimmer, and focus switching is unlocked from the get-go