By progressing the campaign game, new weapons and items are unlocked and become available for purchase. Each weapon and item have various upgrades available that range from Rate of Fire, Power (damage) and Clip Size, to Max Inventory, Blast Radius, etc, as appropriate for the weapon or item.
When playing a Single Mission, a set of weapons, items and upgrades typical for the progression level of that mission will be unlocked.
If you have Road of Devastation you get 2 unique items; Auto-Turret and Medkit.
(Click on the Weapon names for more details)
While this is the starting weapon, with regular upgrades it will remain useful even in the final stages and higher difficulty levels. The specialised abilities of the Rifle are a high powered charged shot (sniper shot) at a lower rate of fire, and unlimited free ammo inventory.
The SMG is the perfect crowd control weapon against weaker enemies for most of the game with its high rate of fire and decent power. It's recommended to upgrade the Max Inventory and Power first, then anything else after as you will find you run out of ammo a bit too quickly. Can also be effective against the special enemies if handled properly.
The old zombie-annihilating favourite returns with a decent set of stats. Its initialy rather difficult to use since it starts off with only 14 shells and a 4 shell clip; However with some thought out upgrades the Shotgun can, and most likely will, be one of the most useful weapons in the game, but it is useful to point out that, it does have a slow reload. (Hint: 2-3 blasts at close range kill most special zombies)
Another crowd control weapon, but best used with care. Its really satisfying toasting a crowd of zombies but be carefull when they get near you since you can burn just as well as they can. Its worth noting that burning zombies are slowed greatly and their movement is disorganized while they are on fire; Also, there is one basic zombie type (Firefighters) that is fully immune to fire. Still a pretty useful weapon when used correctly.
With such a name, you'd expect this to be a fantastic weapon ... and it is once its fully upgraded. Most effective when fired down corridors; this weapon fires a huge lawnmower-like blade straight ahead decapitating most, if not all zombies in its path. When you first get it, the blades are quite small and there is very little ammo available, but if you invest into upgrades then this becomes one of the most deadly weapons in your arsenal
Your basic run-of-the-mill Rocket Launcher with limited ammo and a huge payload. If you purchase this with the expectation if becoming an unstoppable force, you will likely be disappointed. Instead of the rocket detonating upon impact, it detonates when it's in close proximity to any zombie which can prove to be detrimental when aiming for the center of a group. However, if you're needing a supporting weapon and have about 250,000 gold hanging about, then the launcher proves to be a safe investment.
The last weapon to purchase should be the most devastating, and the Shocker definitely is that and more. When fired, it shoots a 'bolt' of sustained lightning which is powerful enough to kill a mob of zombies in mere seconds. The main disadvantage of this weapon is its ammo consumption, but if used correctly by sweeping over crowds of zombies in short bursts, you can clear a crowd of basic zombies without much problem. It's satisfactory against the special zombies, but if there are multiple present at once, then item use may be needed.
Used purely as a distraction, a thrown flare lasts up to 5-6 seconds when fully upgraded and causes any zombies in the area to crowd around it in awe - instead of chasing and attacking you. Used properly, you can clear entire waves of zombies with one Flare and the default Rifle with little difficulty.
Following the vein that zombies like beeping, these Grenades have been fitted with beepers so they attract the horde before detonation. The Grenades have timers of about 2 seconds, so throw them towards the core of the group for best effectiveness. As with Flares, it's recommended to upgrade your Max Inventory for these rather quickly since these can prove beneficial in tricky situations.
Mines are best used for the defense of a fixed location, a situation you will come across a few times while waiting for an elevator or a bridge to extend, or fighting off multiple waves at a crossroads. Careful deployment of mines can be vital in their use to maximise the number of zombies held at bay. Mines are also fitted with beepers so they attract zombies for a while after activation. Note that upgraded mines are multi-use; the number of charges (amount of explosions from one mine) remaining is shown by the rotating red lights on the mine.
This is a really situational Item. Instead of creating a large blast of fire, it only creates a thin and wide line of fire perpendicular to you. Since fire slows zombies, its amazing when used in a bottleneck against a rush, but pitiful when used in the open. If you decide to get the Flamethrower, you could pass these up, but they have their uses if you fancy saving a bit of cash.
We all know the destructive power of Dynamite and so did the developers. They gave us the ability to carry only two at once, but each one has a blast radius between 2-3 times the size and twice the explosive punch of a fully upgraded Grenade. This can easily wipe out an entire horde of zombies and even cripple the special zombies, just make sure you don't waste them. Helpfully, this acts as a flare too, in order to attract zombies.
A deployable turret that shoots nearby zombies. The upgrades allow these to carry more ammo and you to carry more of these. They have a blue circle around them to show you how far they can shoot. Found only on the Road of Devastation instead of the Molotov.
A Medikit that you carry with you and can use whenever you feel like and it heals you to full health. You can only carry 1 with you at all times however. Cannot be upgraded or bought in a shop (any type of shop). Only found as a Pickup inside a crate on the Road to Health on the Road of Devastation (as a DLC add-on, or in Apocalypse Edition).