Oh look it's a new player advice post. I didn't notice this thread but it might be useful to anyone whose new and happens to want to try Dota.
What is DotA (2)?
Dota 2 is simply a remake/update of the original Dota done in a different engine, with the benefit of a team of professionals to support it. Because of that, it makes sense to start off with what Dota is:
DotA, or Defense of the Ancients, is a Warcraft III mod that involves two teams of five players competing against each other to take down their opponents' bases. While the base engine of DotA may have been an RTS, the game plays more like a hourlong RPG; each team's army units (known as "creeps") simply attack move to the enemy base in three lanes (bottom, middle, and top) and each player in DotA controls one of 100+ heroes, and gains gold and experience to buy items that can drastically boost their powers. As a single game takes around 40-60 minutes and every individual member is integral in the team's success, the game is highly competitive!
DOTA2 has a full team at Valve working on it. Most importantly, Icefrog, the current developer of WC3-DotA is working on DOTA2.
Who plays DotA?
Almost 10 years after the first versions of Dota, Dota has an estimated 10 million players on battle.net, Garena and other servers. It's up there with LoL and WoW as one of the world's most played games, and new Dota patches can get up to 6 million downloads a day.
Of course, with Dota's nature being what it is, it has a thriving competitive scene which is alive and well to this day.
From the Chinese dynasties CCM and LGD frought with succession drama to the old-school European dominators like MYM, OK, and Na'Vi, competitors are drawn from all over the world. This large playerbase contributes to a diversity of playstyles and strategies, and the large hero pool and monthly patches ensure that the game never gets stale. Recently as well, Starcraft I/II heavy hitters TeamLiquid have officially began supporting DOTA2 as one of their games. You can now find competitive info and a TL team, just check their site!
NEW PLAYERS
Should I just do bot games until I'm pro?
Some people find that bot games are less anxiety producing than jumping straight into a normal match. This may be true, but you'll see from even a bot game that there are plenty of people just as bad as you are. Still, I think I'd recommend your first game be a bot game just so you can get a feel of how the game controls, and how you buy things from the shop.
The game's got a few handy dandy tutorials to help acclimatize you to everything.
What hero should I play?
General recommendations for new players include
AGI: Viper (Carry, Ranged) or Ursa (Carry/Ganker, Melee)
STR: Sven (Carry/Ganker, Melee) or Tidehunter (Support, Melee)
INT: Lich (Support, Ranged) or Shadow Shaman (Ganker/Support, Ranged)
AVOID: Chen, Enchantress, Meepo, Visage, Invoker, Brood Mother, Medusa, Spectre, Phantom Assassin, Faceless Void
Typically when you're newer, you'll want to stick to heroes who don't have complex interactions with their skills, as well as ones that need a lot of gold to do their job. The characters I suggested avoiding either require micromanagement of several units, lots of gold to work well, or in Invoker's case, learning quite a few new unique mechanics.
IF YOU'RE COMING FROM LEAGUE OR HON: Welcome! Read the Transitioning to DOTA guide at the bottom of this post
This sounds awfully similar to...
Yeah this will sound like all those other games (Dota-likes, AoS, MOBA, ARTS, whatever you want to call them!) like LoL, HoN, Demigod or whatever. Make no mistake though, DotA2 may be prettier and have some new tricks, but in terms of mechanics and gameplay, it is the direct reincarnation of DotA.
Sounds good, how do I play?
Dota2 has officially launched! Just start up Steam, search for Dota 2, download and play!
There's no way to play without a Steam account, but I figure most people who'd read an internet gaming subforum probably have a Steam account..
Transitioning to DotA
League of Legends
-Where did all my mana just go?
You spent it all on that one ability! Generally mana pools start out much smaller and abilities are much more expensive. Some Heroes can't even cast a spell more than once off a full bar at level 1. Don't expect to be aggressive from level 1 in the same way you can in LoL. You will eat through your mana potions and sit there vulnerable.
-What are all these stats? How do I build Bloodthirster?
Itemization in DotA is very different than LoL. All Heroes have three stats, Str, Agi, Int. Str increases health and health regen. Agi increases armor and attack speed. Int increases mana and mana regen. Each hero has one stat as their primary, increasing that stat increases your attack damage. Itemization is pretty confusing but you can still build +damage and +attack speed.
-That's cool, but where's my AP, how do abilities hit harder?
As a general rule, ability damage only scales with rank, unless it explicitly scales off something else. Some items and abilities reduce magic resist, which effectively increases damage, but it's impractical to explicitly stack these.
-Where are the bushes? How did that guy disappear up some stairs?
Dota has no tall grass, it does have elevation. You can't see up onto higher ground so try to always ward higher ground as it gives more visibility.
-Hey, where did my gold go!?
You dropped some of it when you died. You can never lose gold from killing other Heroes. Other gold is "unreliable."
-What's this courier thing?
You don't have to go back to the fountain to buy. You can buy from anywhere! However, you can't retrieve the items you bought until you go back to the fountain and pick them up, or have the courier deliver them to you.
-How do I b?
You have to buy teleport scrolls. You can teleport with them to any friendly tower or your fountain. It's a quick cast and isn't interrupted by damage so you can use it as an escape against anyone without an interrupt.
-This store is confusing!
Yeah, pretty much. In addition to the stat stuff, nearly every higher end item has an on use effect or passive or both. Make sure you read up on items and make sure to use their abilites! Also each side has a "Secret Shop" in the jungle you have to go to for certain items.
-Some other notes:
Last hitting during early game is comparatively difficult to LoL since you do a very small amount of damage to creeps.
Press A then click to last hit your own creeps for denials.
Top and Bottom are not symmetrical.
The jungle is huge and confusing as shit I'm still working this out also stuff hits hard.
Alt is ping, Y is a chatwheel.
There are gems in the river that do things! Just ping them for your team since you don't know what you're doing.
Places on the map with eyeball graffiti are good places for wards.
There's like 900x more CC abilities in this than LoL, watch your positioning.
Heroes of Newerth
-If you played HoN during it's beta, it won't be all that different for you. If not, read on!
-Turn rates are drastically slower in dota than in HoN. This is at the top because the first thing you'll think upon playing your first DotA2 game is 'why is it lagging'. It isn't lag, heroes in this game have slower turn rates, and in some cases slower cast times (think pre buff Jereziah or Torturer)
-There is a secret shop where HoN has observatories, as well as side shops. Some items are only available at these shops, and cannot be bought in base.
-Many heroes that HoN has that came from DotA have been reworked in HoN or DotA since they were transferred. Important examples include Rampage/Spiritbreaker, and Keeper/Treant
Smite
-heh