All the important questions: Who, what, and why
The reason the bottom lane is so important is pretty simple. Over the course of a normal Dominion match, there are two main points that are sieged frequently. The first is the Windmill, the top capture point. The windmill is equally distant from both spawns, so it is considered an even battlefield for both sides. If a team controls the Windmill and both of its home points, the enemy team's nexus will bleed health and eventually die.
However, the two bottom turrets are directly adjacent
, as I mentioned a few weeks ago. This means that the enemy bottom turret is relatively open to attack, and minion waves will spawn from either side and try to capture. If you capture the enemy's bottom turret, you do not have to control the Windmill to deplete the enemy's nexus health -- you fulfill the requirement of "more points held than the enemy." It is difficult to hold the enemy bottom turret for long periods because it is close to the enemy base and the enemy will be able to purchase items and recuperate. However, holding it for even a short while often buys your team valuable time to regroup and capture the Windmill or even backdoor the enemy mid point.
Thus, no team completely neglects the bottom lane for long, and one person is usually assigned as the caretaker of the lane. This job is often thankless, as being successful while doing it usually results in getting ganked or double-teamed. When most people are doing well, it usually results in kills, forcing the enemy to retreat or capturing the enemy points. When the bottom lane champion does well, he usually ends up dying when four enemy champions go down to kill him. Because this role is critical, it's important that you understand that getting double-teamed is a part of the lane and usually a sign that you are doing well.
Since minion waves spawn at each turret and head toward the enemy turret, a large portion of bottom lane is about pushing
. In fact, it's very similar to the laning phase of Summoner's Rift, although Dominion bottom laners want to be much more aggressive with pushing the lane. This is partly because dying is slightly less awful in Dominion and partly because ganking the bottom lane usually hurts the ganking team as much as the ganked team (in terms of lost time).
Because the bottom lane is so push-oriented, leaving the lane is hard to do. Going back to base usually means the enemy will push the lane all the way to your turret, and if you were breaking even before, it might result in losing your turret. This means that sustainability, both in terms of health and mana/energy, is very important. There is a health relic above the centerpoint of the lane, and fighting over it is common as the little boost to health and mana usually grants a big advantage to the player controlling it.
However, there is another strategy besides pushing. Some champions can simply be aggressive and either force the enemy out of lane (like Yorick or Urgot) or kill the enemy outright (like LeBlanc or Talon). Aggressive characters, like Riven, Vayne, and Poppy, make interesting alternatives to some of the more passive, poke-oriented bottom lane choices. Doing this can be dangerous, though; the enemy may field a character that does well in such situations, or the enemy player may simply be experienced fighting aggressive players. In these cases, you may want to call for a lane switch if another character is more suitable for standard laning than yours.
Ganking the bottom lane is somewhat of a last resort. However, there are times when it can be beneficial. If your team is unable to win teamfights elsewhere, putting pressure on bottom can be a smart play. This is one of those strategies that comes with practice. Avoiding the meta altogether (putting two bottom or pushing and leaving) is better suited to premade teams.
While in bottom lane, it's very important that you remember to last-hit
. In Dominion, last-hitting is less-emphasized because there is passive gold gain. However, last-hitting gets you ahead of the enemy! A single minion wave of three puny minions is worth 120 gold. Don't let that cash go to waste!
Matchups and metagame
A bottom lane matchup is largely dependent on two factors: push and harass. A champion with excellent push will eventually force down the enemy's turret with minions, while a champion with excellent harass will keep the enemy from pushing and can push himself. A third element, sustainability, is of varying importance depending on the amount of harassment that your enemy is using. The more she harasses, the more health sustain you'll need. Likewise, characters with strong push or harass but poor mana sustain (like Anivia or Orianna) cannot hold the lane for long periods without mana regeneration items.
In my opinion, the best pushing champions are those with strong AoE damage -- specifically, AoE that doesn't scale downward against more targets. Heimerdinger pushes very well for instance, but he lacks AoE damage until his turrets hit max level, and at that level the turrets are subject to minion damage and enemy champion attacks. The reason I pick on Heimer a bit is that good AoE pushers are also excellent counter-pushers. If your lane is getting pushed heavily, a good AoE champion like Morgana or Cassiopeia can drop one AoE patch and wipe the whole wave. Even if you're being heavily harassed and can't really push up the lane, you can usually safely clear the wave, which takes a lot of time to build back up. In particular, Morgana is really good at this role, as her Tormented Soil heals her and her Black Shield can be used to shrug off most harass to throw the soil down. It can also prevent assassinations from characters like Talon or Kassadin, who can't silence her while her shield is up.
The best harassing champions are not much different than in Summoner's Rift. Ryze, for instance, doesn't have the best range but he builds a lot of tank and can eventually just ignore his enemy's damage and bully her out of lane. Cassiopeia has huge range, and her poisons allow her to spam her extremely damaging Twin Fang. This makes players want to disengage any time they get poisoned, which in turn allows Cassiopeia to push the lane. In general, if a character is strong in the laning phase of Summoner's Rift, he or she is probably pretty good in Dominion's bottom lane. There are exceptions: Characters with poor pushing power (such as Viktor) generally cannot do well in the bottom lane. Ziggs has to choose between pushing the lane and harassing, making him a weaker (though not terrible) choice.
One of my long-standing jokes is that bottom lane is a rock-paper-scissors between Urgot, Cassiopeia, and Talon (Cassio beats Urgot, Talon beats Cassio, Urgot beats Talon). You can safely swap Yorick for Urgot and Kassadin or LeBlanc for Talon in these matchups. This little circle is a pretty safe group of characters. Cassio, Urgot, and Talon beat a lot of bottom lane champions, so I definitely recommend learning how to play as and against all three of them and probably their alternates (especially Yorick) as well.
This is not to say that they are the only viable options. In fact, there are a few -- Soraka and Mordekaiser in particular -- who don't fit in that circle cleanly and have good or even matchups against many of the best choices for bottom lane. Skarner is also a weird character with specific counters who beats many of the stronger bottom lane choices.
Ranged autoattackers like Vayne, Caitlyn, and especially Sivir can perform well in the bottom lane. Much as in Classic, these characters perform better later in the game. I've found that, generally, once one of them gets a Sanguine Blade, it's very hard to do anything to them. These are some of my hardest matchups.
In general though, any champion with strong AoE that has decent mana sustain (not Anivia) can do well in the bottom lane. If you want to improve your win/loss record, start learning a good bottom lane champion and practice, practice, practice!
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