Worms Forts: Under Siege is a turn based strategy game by Team 17. It is a 3D worms game which involve controlling worms and using a majority of weapons to kill the opposing. This worms game includes a new feature, which are buildings. Like previous Worms games, players can still win by killing the enemy team/s, but now, with buildings, a team can win by destroying the enemy stronghold. This game also adds siege weapons which replace or remove many of the old weapons in previous games.
There are 9 types of buildings in Worms Forts: Under Siege, some of which require 'Victory Locations' these include:
- Strongholds - The most important building in the game, all other buildings must be connected to the stronghold. If a teams stronghold is destroyed, then they lose.
- Towers - A building which can fire Tier 2 weapons.
- Keep - A more powerful version of the Tower which now includes the ability to fire Tier 3 weapons and requires 2 Victory Locations.
- Castle - A strong building which can fire Tier 4 weapons and requires 3 Victory Locations.
- Citadel - Almost as strong as a Stronghold, the Citadel can fire Tier 5 weapons, the most powerful of them all and requires 4 Victory Locations.
- Hospital - The hospital can spawn deceased worms, but with small health. It requires 2 Victory Locations.
- Weapon Factory - This building is very weak but can spawn weapon crates around it and requires 3 Victory Locations.
- Science Lab - The Science Lab increases the damage that weapons can cause and requires 4 Victory Locations.
- Wonder - A strong building which, if is not destroyed within 2 turns, the team who built it wins. Requires 5 Victory Locations.
The weapons used in Worms Forts: Under Siege are mostly fired from these buildings, although there are a few that can be fired from the ground. These are:
Firstly, the ground weapons, which require no buildings to be fired from:
- Bazooka - A weapon which is effected by the wind and deals up to 45 points of damage to a worm, and 25 to a building.
- Grenade - Slightly more powerful than the bazooka, dealing up to 50 points of damage to a worm. The fuse can also be changed.
- Airstrike - A bird flies over and drops 5 bombs over the designated area. It is effected by the wind
- 50 Stone Canary - A bird which does up to 45 points of damage which can jump after it has been released.
- Electric Storm - This weapon, when used, goes over enemy buildings and rains down household appliances. It doesn't do much damage to a building but it does good damage to a worm.
- Fire Punch - This punches an enemy worm away from the users, taking off 30 health points from the victim.
These are followed by Tier 2 weapons, which are fired from a tower:
- Mortar - The mortar fires a man up into the sky and when it hits something solid, he explodes into several clusters. It is also affected by the wind.
- Cluster Launcher - Similar to the grenade except when it explodes, it releases small clusters. It's fuse can be set.
- Napalm Strike - A bird swoops down on the designated area and releases bombs which is very effective against buildings and causes a fire.
- Old Women - An old women with a 30 second fuse and can be manually blown up. She is controllable and can jump.
- Earthquake - Shakes the whole landscape causing worms to roll around into water, mines, fire or nothing at all.
- Ballista - This crossbow fires burning arrows which explode on impact. It is affected by the wind.
Then there are the Tier 3 weapons, which are fired from a Keep:
- Siege Onager - Affected by the wind, this weapon fires 3 burning balls of fire which explode on impact.
- Chilli Con Carnage - Once the Mexican has settled, he explodes, releasing mini Mexicans which also explode and leave behind some fire.
- Mine Strike - A bird drops 5 mines down on the designated area although they do not trigger when dropped on a building, only worms.
- Rhino - A rhino who's trajectory can be set, it does damage to all buildings it collides with and enemy worms.
- Flood - Temporarily raises the water on the landscape, drowning any worms who are low enough on the ground.
- Minigun - This gun does considerable damage to worms and building although it does have a bad recoil.
Then the Tier 4 weapons which are fired from a Castle, some of these, marked with * must be unlocked in the games campaign mode:
- Homing Pigeon - A bird which flies to its set target and explodes on impact.
- Fridge Launcher - A fridge that bounces around until the fuse runs out and then releases frozen food. The fuse can be set.
- Animal Strike * - A very powerful weapon which does a lot of damage, it releases animals down onto the landscape and they explode. They can be manually triggered and they bounce around a bit.
- Super Hippo - Players can release an explosive hippo that can fly towards a target.
- Nuclear Strike * - This drops a nuke down and makes all worms sickly green, and they lose health each turn. Sick worms can be healed by picking up a health crate.
- Giant Crossbow - This crossbow fires in a straight line is only slightly affected by the wind. It is very shaky and hard to keep it on target.
Finally, the Tier 5 weapons, the strongest of the lot, fired from a Citadel, once again, some of these must be unlocked in campaign, marked with * and some must be unlocked in the Deathmatch Challenges which are marked with **
- Rocket Launcher - A giant pipe organ which fires five rockets down onto its target. It is also affected by the wind.
- Trebuchet - Once of the most powerful weapons in the game which does enough damage to destroy a stronghold. After hitting an object, it bounces around until the fuse runs out.
- Trojan Donkey * - A replacement for the Concrete Donkey, as the landscapes are indestructible, it does not bounce and destroy the location it is on, instead when it lands, it blows up randomly during a turn.
- Monkey Troop * - This weapon releases a bunch of monkey's which do quite a bit of damage to a stronghold or citadel. Players can make them explode manually.
- Armageddon ** - Raining down meteors onto the level, it does considerable damage to worms and buildings.
- Giant Laser - A very destructible weapon which fires in short bursts doing a lot of damage to buildings but will not blow a hole into the side of a stronghold, although it easily destroys towers and keeps.
- Jetpack - The Jetpack can help players travel long distances in length and height. Unlike previous worm games, players cannot drop weapons whilst using it.
- Freeze - Freezes an entire team of worms and buildings until their next turn, making them impossible to destroy, although this does not effect the wonder.
- Parachute - When players are falling, using the parachute will soften the fall.
- Girder - Players can use the girder to protect worms or buildings and make ramps up to inaccessible areas. Its position, angle and height can all be altered.
- Repair Building - This repairs the selected building.
- Spawn Worm - If players have a hospital and a dead worm, this utility can be used to bring it back from the dead. It can be used up to three times a turn.
- Double Turn Time - This automatically doubles the time that a player has per turn.
- Double Damage - This does double damage during a players turn; it is used instantly.
- Crate Spy - Once this is collected, the team who collected can see what is in the crate drops for the rest of the round.
- Skip Go - Skips the turn of the current worm.
- Surrender - Surrenders the team and removes them from the round.
There are also stories in the games campaign mode which are:
- Egyptian - This story focuses on a worm named Seth, who wants the player to help him raise an army of the dead to battle the Pharaoh.
- Greek - This story focuses on the Trojan War against the city of Troy where players must save Princess Helen from Prince Paris.
- Oriental - This story focuses on the Mongol Invasion.
- Medieval - This story focuses on King Arther and how he had become King.