Objective-based match types where you win by passively accumulating points can be a bit, well, uneventful. Holding or assaulting a base isn't uneventful, of course - particularly if, like me, you lose the ability to distinguish between friends and enemies once your blood pressure reaches a certain level. But as a rule, one team will eventually gain an unbeatable lead and proceedings will slope depressingly downwards towards a climax-deficient, mathematically determined finale. Boo.
By contrast, every round of Dominion in Halo 4 culminates in a frenzy of vengefulness and yelling. The second one side captures all three bases, the other team loses the ability to respawn and a Sudden Death countdown begins, regardless of point totals. If you're in the lead, that's your cue to howl like a wolf, leap aboard the nearest Ghost and start firing indiscriminately (assuming you were firing discriminately before). If you're on the losing side, that's also your cue to howl like a wolf, leap aboard the nearest Ghost and start firing indiscriminately.
Oh, I'm sure there are shades and degrees between "going postal" and "turning the other cheek like a big wet nancy" - ousted teams might want to pull together and focus their efforts on a single base, for instance. But the lure of merciless/defiant savagery is hard to resist. Kick them when they're down? Absolutely - but only if you can't drive over them when they're down. Or launch gobbets of shimmering green death at their gonads.
My first crack at Dominion occurred on the Longbow map, a purple-greeny number which manages to create discreet firezones without spreading its tactical landmarks miles apart. Two bases sit below and in front of a third, separated by steep hillocks and metal barriers. As on most Halo maps, there are sneaky side routes to each base, and as on most Halo maps, it's enormously easy to catch somebody emerging from one of those side routes given advance warning of their filthy underhand tactics.
Bases themselves are walled and roofed enclosures with two or three entry points - tough to crack, especially when the defenders are wielding ricochet-happy Forerunner Scattershots, and especially especially once said base has been fortified. Fortification unlocks vehicle spawn points, automatic and/or manual turrets and door shields, while subsequent resupplies replace any destroyed facilities.
Both happen automatically after you capture a base - they both take about 45 seconds, off the top of my head - but any enemy interference with the capture terminal will reset the countdown. What does this mean? It means that even an aborted assault can be effective, denying your enemies that Scorpion for a crucial additional handful of seconds. Victories are pieced together from such scraps.
Dominion lacks the grandeur of a round of Conquest in Battlefield, but as far as Halo objective capture goes, it's going to take some nobbling - a sexy sandwich of chaos and calculation.