Easy Cash and XP
At various points throughout the campaign, you can buy items cheaply and sell them for substantial profit and experience. An example of this technique can be found in Henderson, where a doctor sells medical supplies. Once you have the option to purchase bleach, make sure that you buy as much of it as you can afford. To the southeast, you'll find the makeshift hospital, where you rescue Nina. After doing so, head back to the hospital, where she will offer an ongoing quest. The bleach that you previously bought for $168 can now be turned in for around $1200-$2100, with an accompanying reward.
Duplicate Melee Weapons (Riptide; error from first game)
To duplicate a melee weapon, start by equipping it from your inventory. Throw the weapon and while it is still in the air, quickly press the appropriate button to access your inventory. Unequip the weapon that you just tossed, then exit out of your inventory. Now you can pick up the weapon and your inventory will show that you now have two of that weapon. This is a great way to earn money quickly, by selling duplicated equipment.
Carry Additional Weapons
When you are playing as John Morgan, enter rage mode. John will pull out a staff, which is separate from his standard inventory. If your inventory is full at that point and another weapon pickup is nearby, you can quickly select that other weapon to replace the baton that John is carrying. That will add an additional weapon to your inventory, so that you are now carrying more than the usual maximum of 18 weapons. You can continue to expand your inventory in this manner, by activating rage mode and swapping out the baton for addition items as your inventory swells.
- Achiever - Finish all quests in the game
- At Your Service - Rescue 20 NPCs from clench
- Better than the arm - Kill 25 zombies with a chainsaw
- BrainLess - Kill 50 zombies by smashing, decapitating or shooting them in the head
- Breaching the Tunnels - Successfuly defend the tunnels entrance
- Bully - Kill 100 zombies with a kick.
- Combat on the roof - Survive the horde on the roof
- Deafeat Harlow - Deafeat Harlow
- Dream Team - Complete all the main quests cooperatively with any number of partners
- First Do No Harm - Finish quests for Cecil in hospital
- Gain level 50 - Gain level 50
- Gain level 70 - Gain level 70
- Heart of Darkness - Find a boat to travel through the jungle
- Henderson town - Reach Henderson
- Hunter-Seeker - Find and kill all named champion monsters located in dead zones
- Hurler - Kill 100 zombies with thrown melee weapons
- It's an order - Mark 100 opponents which then were killed by your coop partners
- Jetboat - Kill 100 zombies using boat speed boost
- Juggernaut - Kill 100 enemies using charge attacks
- King among kings - Kill special enemies: Grenadier, Thug, Wrestler, Infected, Suicider, Screamer, Butcher, Floater.
- Meeting Serpo - Make pact with Serpo
- Military Base - Gain access to a long range radio station
- Mystery solved - Find all the secret files of Consortium
- NewsJunkie? - Find all voice recordings of a journalist
- Professional Tourist - Find all pages from the guide book
- Serving Science - Finish quests for Dr Kessler
- Siege Hammer - Install 5 barricades in any hub
- The Cinema - Clear out the cinema
- The Collector - Find 50% of collectibles
- The Docks - Enter the docks in Quarantine Zone
- The Hoarder - Find all collectibles
- The Hurt Mine Locker - Kill 10 zombies with one mine
- The Storm - Escape from the ship
- Twins - Kill the Twins
- You've tricked me once - Finish the game