Well, I see a lot of misinformation and repeated questions going on around the new players.
I propose making a page with the following info, mostly so when someone makes the same post we have seen already, we just post a link to this FAQ and be done with it:
Add/fix anything you think is relevant, then we'll get it on the wiki if there are no objections.

Party / levels:
* Everyone gets every crown picked up. They are not divided.
* Everyone gets every heat picked up. It is not divided.
* Everyone gets every token picked up. They are not given to a single party member.
* Mats are randomly distributed between party members.
* Heat is collected during a level, but only gained after clearing it.
* Everything that is not heat is gained as soon as it is collected.
* You can resurrect a dead party member by attacking while standing on top of him/her and giving him half your health. Doing so will give the 30% of heat the dead person dropped when they died.
* Resurrecting using CE doesn't give you back the 30% of heat you drop when you die.
* Every time you go down a lift, if you had less than 3 health, you get your life filled up to 3 health.
* If someone is dead and everyone else gets on the lift to the next level, the lift goes down, the dead person doesn't gain any heat, but is revived automatically with 3 life at the next level.

Bonuses / gear:
* Equipping an item makes it impossible to trade. You can trade it if you upgrade it via crafting and don't equip it again.
* Gear can be bought from vendors, other players, or crafted. Crafting requires a learned recipe, materials, crowns, and energy.
* Gear levels up to lvl 10 maximum
* Leveling up equipments raise their stats up to the limit of the shadowed area of the stat bars.
* Heat is divided evenly among all the equip that needs to be leveled.
* Most weapons get charge time reduction bonuses at level 5 and 10.
* Each time you craft there is a chance of getting an unique variant (UV) of an item, with a random bonus, offensive for weapons, defensive for armor.
* The UV is displayed yellow with a star, and can be transferred to the higher level version of the same item when crafting
* Bonuses are additive, not multiplicative. Bonuses can be negative.
* Weapons can have offensive bonuses. Armors can have defense and/or offensive bonuses.
* Offensive bonuses are percentual. They cap at maximum.
* Attack speed increase value for swords has a hard cap, which mostly affects the cutter/spur line.
* Defensive bonuses are static and additive.

Progress:
* Playing Tier 2 requires having at least a 2 stars armor/helm/shield/weapon and having cleared at least 15 Tier 1 levels. Then talking to the ward at Moorcraft (depth 8 of any gate).
* Playing Tier 3 requires having at least a 4 stars armor/helm/shield/weapon and having cleared at least 25 Tier 2 levels. Then talking to the ward at Emberlight (depth 18 of any gate).
* After you have access to tier 2 or 3, you can start a party at Moorcraft/Emberlight, or join parties in those tier depths.
* Starting/joining a party costs 200 crowns for tier 2, and 500 for tier 3, unless you previously cleared the previous tier of that gate.

Energy:
* 100 mist energy recharge over 21 hours.
* Crystal energy (ce) can be bought from other players in the ce market with crowns, or with money from Three Rings.
* Mist energy is shared between account playing from the same ip or computer, unless one of the accounts has ever payed for any energy with cash
* If you feel you need to post on the forums about the system, please don't make new topics, use an existing one.

Gate construction:
* Different combination of minerals make different stratums, so it's best to try to get different combination on different gates instead of autoselling.
* A stratum determine which enemies will appear in a given segment of the gate
* A segment goes from the start of a tier to a terminal, or from a terminal to the end of the tier.
* There are two type of levels, premade levels have always the same design, and randomly generated levels are made from different premade blocks joined together.

Haven:
* There are many instances of Haven, you can switch between them by clicking over Haven X on the top right of the screen.

Troubleshooting:
* Check this sticky first: http://forums.spiralknights.com/en/node/48