Around 20 years ago, I used to play a game on the Apple II called Rescue Raiders. On the surface, it was a simple 2D Choplifter-style game where you piloted a helicopter and blew things up. But it had another aspect to its gameplay - you had to also build tanks, troops, and some other vehicles and get them to the other end of the map so they could blow up the enemy base. Of course, there was an AI-controlled enemy chopper doing the same thing.
Rescue Raiders was one of the first games I can remember playing that had autonomous non-player characters that were critical to the game - but you had basically no control over them and could only indirectly affect their fate (for example, by buying them in the correct order and escorting them to make sure your troops weren't firebombed by the enemy helicopter).
I never played the original Dota (or League of Legends, or any of the other MOBA/ARTS class of games that are so popular nowadays). I'd avoided Dota primarily because I'm an FPS guy with some slight RTS tendencies, but also because I'd heard it had a pretty toxic community, which turned me off. However, when I played Dota 2 for the first time, I had instant flashbacks to playing Rescue Raiders - the creeps are vaguely analogous to the tanks, anti-air trucks, and troops that I had so much fun sending to a fiery death in Rescue Raiders. So I liked it already.
...I find it amusing that my game playing is basically being subsidised by a primarily male population of video gamers who - when it comes down to it - like to dress up virtual dolls...
For those who came in late, games like Dota are a little bit of a mix of everything. There are some classic RPG elements - you pick a character and have to level him through the game. There's a lot of real-time strategy - you're working with teammates to accomplish a common goal. But explaining what you actually do turns out to be sort of complicated. Remember, it makes a lot more sense when you're actually playing.
Dota 2 is a multiplayer game (though you can play against bots). There are two teams of five players - the Radiant, and the Dire. Each player picks from a list of many characters, each with a different set of abilities. The two teams start on opposing sides of the map (there's only one map in the game). Each team has a base area, in which resides an "Ancient". From each base, creeps - these autonomous NPC creatures - spawn periodically in waves, and start a journey toward's the other teams base. Towers are scattered around the map that will automatically fire on any enemy unit.
The goal for each team is to destroy the other team's Ancient, while defending their own. Hence: Defense of the Ancients.
Sounds simple - but there's a lot more to it than this. Imagine the game starts and both teams just stay in their own base. Creeps from both teams will wander out from one base and head to the other, meeting somewhere in the middle of the map, where they will fight (again, they do this automatically without any player input). The creeps are evenly matched so typically they will both wipe each other out. The next wave of creeps will clean up anything left over - or they'll reach a tower, and get smashed by it - and the cycle will continue.
Basically, nothing will happen - the game will not end, because the creeps can't get anywhere. Now imagine just one player from one of the teams goes out with his creeps. He can attack the enemy creeps, and support his own creeps as they make their way across the map, knocking down towers along the way. Eventually, he'll get to the enemy Ancient, and be able to destroy it. But if just one enemy player comes out to meet him, the teams will be more evenly matched - and it comes down to a player versus player (PvP) scenario.
The PvP is, of course, the heart of the game. It is of a high level of complexity - the learning curve is quite steep, making it challenging for noobs, which is one of the reasons why the community was famed for being full of what I will euphemistically call "short tempered people". One player who doesn't know what he is doing can easily bring down the whole team.
The complexity comes from two main parts - first, the sheer number of selectable characters in the game. At the time of writing, there are 102 characters - with more added periodically as the game is updated. Each character has four different abilities (sometimes more) that are active (requiring the user to press something to make them go) or passive (they just operate automatically). The abilities are character-specific, though there are common elements between them. Some of the abilities require chaining to use them effectively, and each ability is leveled individually as your character earns experience.
After you've done the maths and figured out how many different abilities there are between all the characters - and thought about how long it would take to become familiar with even a small handful of them - consider that in addition to that, there are over 120 different items that you can equip your character with. Items can perform new actions or augment your existing ones (again, they are active or passive in nature).
Oh yeah - each game takes a long time to finish - around 45 minutes is pretty common. You will never get away with saying "I'll just have a quick game of Dota" to your significant other - at least, not once they've put up with you playing it a few times.
So - learning curve. Big one. Time investment (or sink, if you prefer). Big one. Especially when you're trying to play with other people and they're abusing you for not knowing what you're doing. But the real question is - is it worth it?
I've clocked up almost 400 games (and there's still some characters I haven't played). I'm not turning pro any time soon, but have a reasonable handle on the fundamentals. My win rate is about 50%, which seems to be fairly normal. Losing is often traumatic, especially after you've lost a couple of long 45-60 minute games in a row, or you're saddled with random teammates in the matchmaking who are abusive idiots (or just bad).
But the games that are good - they're really good. With so many combinations and different ways to exploit them, the level of satisfaction when you're playing with friends and manage to co-ordinate a five-person push on a tower, laying down that perfect combo that takes advantage of all your abilities, wiping out the other team.... well, that's what keeps me coming back for more.
Not only that, but once you've invested a bunch of time and gotten over some initial learning humps, it's genuinely fun exploring the different characters and item combinations. There are always new builds to try and new items to buy. I've gone through several "favourite characters", depending on which new ones I've played recently and how well they worked out with my natural play style and with my teammates. Even after around 400 hours of gametime, I still have more to explore.
I do, however, only really enjoy playing the game with my friends. I've tried a few games "solo", just picking up teammates using the matchmaking service, and I find this massively less fun. It's less engaging because I typically don't like to communicate with randoms via voice, and your chances of picking up toxic players are increased. I've had good games with randoms, but generally don't bother playing unless my mates are online.
As with all reviews, this one attempts to help answer the question: "should I buy this game?". Well, good news - Dota 2 is free. It has just come out of a long invite-only beta period, so your actual financial investment in whether or not you should get into the game is zero. But there are two big questions you need to ask yourself:
1. Can I justify the amount of time I need to get decent at this game before I start enjoying it?
Make no mistake, the learning process for this game is An Ordeal. If you're prepared to spend many hours reading guides and playing with bots until you can beat them on a reasonable difficulty - maybe 10 games? - then that's a good start. If you've got mates that are happy to babysit you then that's good - but note that most of them will not want to do this because it almost certainly means they'll be losing (a lot) while you're still struggling with the basics.
The best way to approach it is to read some guides - I recommend Welcome to Dota, You Suck - and play with bots until you can beat them on Hard, reliably, with one character. Then find some friends who are happy to play with you knowing your noob status, and play some games online with them. The more friends the better; if you're matchmaking with randoms they will probably be less tolerant.
2. Why is it free? I seriously can play this without paying anything?
Dota 2 is built on the "freemium" model. It's free to play, and you can purchase in-game items for money. By giving the game away, Valve hope to make more money selling in-game items than if they'd charged for the game. This is an increasing trend - so get used to seeing it more, especially for games with a strong network effect (i.e., anything with multiplayer).
The things you can buy for Dota 2 are basically adornments for the characters. For example, you can outfit them with new armour, or a new sword, or some new spell effects, that are different from the stock-standard one that they come with. You can get some of these for free - they'll randomly drop at the end of games - but the good ones for your preferred characters you'll have to shell out for.
It's very important to note that these items are purely decorative and have no impact on the gameplay at all. You can't pay money for a new sword that does more damage - it just looks different. This is critical and stops the game from becoming a silly pay-to-win thing. If you're a content creator, you can also create your own stuff and sell it in the store (splitting revenue with Valve).
The store is well integrated, and not at all in-your-face; you certainly don't feel like you're constantly being pressured into buying stuff (I'm looking at you, Tapped Out). I have spent a total of zero dollars on in-game items. I almost feel guilty about it, but I have always been completely uninterested in character customisation aspects in any game and am completely focused on the multiplayer experience.
So, you can play it for free, but you can trick out your character if you so desire. I find it amusing that my game playing is basically being subsidised by a primarily male population of video gamers who - when it comes down to it - like to dress up virtual dolls. Keep at it, people!
I could go on and on about Dota 2. It has amazing competitive features - it's trivial to spectate games, making watching the pros play painless and fun. They're running a huge competition with a prize pool that's just passed USD$2 million, funded in part by purchases of virtual items. It's well maintained, runs really well on a variety of hardware and has local Australian servers - I've had two server crashes in almost 400 games. Mac and Linux clients are about to come out. The list goes on.
One final note - Valve have been very active in dealing with the oft-criticised toxicness in the Dota community. They're constantly tweaking their player reporting system, and recent results are promising. Anecdotally, I feel that player behaviour has improved significantly since I started playing - general abuse seems way down as players adjust to the new systems. There'll always be bad eggs, but you can report them, mute them, and move on knowing that - if they are truly douchebags - they'll probably be getting dealt with.
It's an amazing game - technically outstanding, showing all of Valve's usual polish and attention to detail, especially in the all-important multiplayer aspects. The continual balance tweaks and new heroes combined with the vast amount of content in the game offer countless hours of enjoyment. It's hard to master but good wins with your teammates are incredibly satisfying. It took me a long time to warm up to, but I'm helplessly addicted and every day look forward to getting home to fire this up with my friends. If you can spare the time - play it.