Effectiveness: High, as in the previous Halo titles. This time though you can use it against the Flood.
Effectiveness: Low. It was useful in past Halos but now it cannot stay on par with other, more effective weapons.
Fuel Rod Gun
Effectiveness: High. This is an equivalent of a Rocket Launcher, but it has more firepower. It's good for destroying almost everything except fast vehicles (like Ghost).
Effectiveness: High, but you can do well without it. Other weapons are also very effective in hand-to-hand combat, so Brute Shot blade isn't your best option anymore.
Effectiveness: Very high. This weapon has changed the same way Battle Rifle has . Now it's one of the best weapons in the whole game. The worst enemy of Brutes' head.
Effectiveness: High, but it's not as necessary in campaign, as in past Halo games.
Effectiveness: Not a common weapon and less useful than in the past.
Effectiveness: High. When you're out of Battle Rifle ammo, get a Spiker and it will do nicely.
Effectiveness: Medium. Very interesting weapon, powerful but only at short range.
Effectiveness: Medium. Special weapon used only by Brute leaders. It's a melee weapon so it's relatively useless in campaign.
Effectiveness: Very high. Alien equivalent of a sniper rifle.