The Summoner's Rift

Before the Twisted Treeline and the Crystal Scar, there was one map, the original map that most, if not all versions and offshoots of DOTA used. In League of Legend's, it's called The Summoner's Rift, in Starcraft, it's called Aeon of Strife, in Warcraft, it's called Defense of the Ancients. This map is where it all started, the classic gameplay of the DOTA-class games.

Summoner's Rift

Early Game

This is when everyone's really weak, so this is where most of the really successful ganks turn up, as whoever wins the early game usually ends up winning the middle and late game. Minions don't spawn until a minute and a  half into the game, so it gives players time to set up who is taking which lane and getting there as well. Also, a lesser used strategy is waiting inside the enemy's jungle, waiting for their jungler to run to his blue golem or red lizard, these usually work well as not very many teams gather anticipating a raid on their jungle, especially in solo queue. After this you usually go back to your respective lanes and start farming or harassing each other and then you slowly start into mid-game.

Mid Game

A variety of things can happen mid-game, as it all depends on what happens early game. What happens is based on how well your team is doing, how well the enemy team is doing, and what the team composition is. For example, you could have done horrible early game, but if they have really good early game characters and no carries, then mid game, you will start to pick up if you haven't fed too much, as carries tend to be bad early game and really pick up as they get better items and early game champions tend to be awesome right off the bat, but then lose so much power that they are almost useless late-game.

There's also a lot more lane pushing and people aren't as restricted to their own lane as much. This is because the levels between people are uneven so they can take chances and help out another lane.

Late Game

Late game is a much more high stakes place, as people are much more powerful, and without a key teammate in a teamfight, then it could easily end up with you losing the game. This is the time where one AD carry can ruin your base just because he's the only one left, or just because you're off fighting his team, and he snuck in and had his way with your turrets. Individual characters are mega-powerful, and usually people stick together just because of that.