Obstacles

While on missions it is natural for the player to encounter hazards such as traps and enemies. However what makes it neccesary to observe and memorize the way locations can be interacted with is to learn how small details like climate, objects and terrain can affect gameplay both positively and negatively.

Bear in mind that most of these obstacles affect enemies and allies as much as the player characters. Specifics and exceptions will be noted in the descriptions.

Rain[]

Sometimes rain might be falling on a chosen mission location, the rate at which this occurs is seemingly random.

More than decorative, rain affects heavily on some factors of gameplay:

Vision range: Vision range becomes severely reduced during rain. While this often helps the player as it makes it more difficult for enemies to spot them it also makes it more difficult for players to see enemies from afar. Specially notable for enemy ninjas like the Mosu or Kenobi, already stealthy in their normal attire, receive aditional concealment during rain. While not as notable, rain also makes light sources less visible.
Slippery ground: The ground becomes considerably slippery during rain. The players are not much affected while running at normal speed but if they sprint (by pressing "O") it becomes difficult to control the direction of the run, make turns, stop and easy to slip and fall from ledges. Enemies also become affected by the slippery ground, having the same difficulty as the player if they run faster and often tripping.
Sound reach: Because of the sound of falling rain, sound reach becomes lower. Bells, explosions, yelling, dog barking and impacts are muffled and difficult for the enemy to hear, giving the player an advantage. This effect is not total however, and close enemies might still hear the sounds.

Dog Kennels[]

Some locations, specifically "town" and "castle" type maps will have dog kennels in some areas, usually corners. While the dogs are not direct enemies their barking will quickly alert nearby enemies of the player's presence. They only bark if they spot the player and their vision range is similar to that of soldiers.

Dog kennels can be pulled or lifted with the grapple hook or picked up like stationary items. If picked, the proximity of the player will make the dog bark at least once.

The loading screen advice concerning dog kennels is erroneous in some details: toppling over kennels will prevent the dog from barking only if they land upside-down, if they land sideways or diagonally the dog may still pop out to bark at players. Another, more inmediate way to get rid of the barking is to throw kennels into wells.

A dog kennel can be gifted by Ichijo to put in the garden. Likewise, escaping a map with a dog kennel during a New Game+ will make it available as an item in the garden.

Cages and Sheds[]

Most locations will spawn with decorative sheds with sealed doors. In some occasions however the decorative shed may be replaced with one of the following:

Bear cage: The cage contains a captured bear. Getting near the closed cage won't incite a reaction but opening the cage will free the bear inside, which will proceed to attack any enemies they spot like regular wild bears.
Barbarian hideout: These sheds hide groups of barbarians. Opening them will cause a large amount of barbarians to pop out and attack the player and other NPC. The same penalties as being spotted by barbarians apply if the player does not deal with them before completing the mission.
Hostage cell: Only seen during "Rescue" missions. These cages are similar in appearance to bear cages with the exception that they contain target hostages. Getting near them will cause the hostages to scream for help, while opening them will free the hostage who will follow the player as an ally.

A bear cage is one of the items players can buy and set in their garden.

Bottomless Pits[]

Some maps contain bottomless pits, which are an inmediate hazard. Falling into these pits will inmediately result in a mission failure or game over, but they can also be used to dispose of enemies, corpses or items.

Natural pit: These pits are a natural feature of the map, and often wide in diameter. The Phantom Forest has a chasm at the south of the map, Dandala Pass and Rokudo Valley are surrounded by it while Utakata Castle and Fudo Castle have the chasm surrounding the exterior of the castle area.
Pit trap: Normally pit traps are designed to make individuals under it fall a floor below or into another trap, but in the case of traps at ground level it will instead generate a bottomless pit under it. While such a trap is not seen in any map, setting a pit trap at ground level in the garden will also generate a bottomless abyss. Like all traps, they can also be activated by throwing corpses or heavy objects into it.
Well: Wells are a common feature in most maps, and they always generate a bottomless pit inside them. They are always seen in "town", "fortress" and "castle" type maps. They are stationary. If a soldier finds a corpse and there is a well near the area they will pick it up and dispose of it using the well once they drop their guard.

Pit traps can be bought and set in the garden. Likewise, a well will be gifted by Onji once the player progresses enough into the game.

Water[]

Rivers, artificial rivers, puddles and ponds are a common feature of locations. Decorative ponds are found in Honcho Shimoyashiki and Negishi Pavillion. Rivers are found in Sengen Town, Rokudo Valley, and Ryonin Market. Puddles are found in Phantom Forest and one of the corners of Ryonin Market.

They are all functionally the same. Running in a water surface will cause noise that will attract the attention of enemies, same as dropping heavy objects into it. Stealth killing an enemy in a water surface will make the ninja try to drown them into it, taking considerably longer than most stealth kills but surprinsingly the noise itself will not attract enemy attention.

Stationary Objects[]

These are objects, often of decorative purposes, which are small enough to pick or carry. There are a wide variety of them which have different degrees of importance and interaction.

Transport box, money box and rice barrel: Usually the target of Transport, Robbery and Thievery missions, the player needs to exit the map or reach a specific point of the map with it to complete the mission. They, like most decorative objects are sturdy and will resist explosions and hard falls, but dropping them into bottomless pits will count them as lost, causing the failure of a mission (unless there is more than one of the same box/barrel in the map).
Decorative object: These objects are put as decoration in a map. They can be carried and thrown, and come in small and large varieties. Running into them (pressing "O") will make the player trip, as well as enemies who do the same. Some objects can make navigation easier, for example, dropping a box near the wall surrounding Utakata Castle (the area with the watchpost, the well and the boxes) can allow a player carrying a heavy object to jump over it and throw the item they carry outside, landing near the exit and saving them time. Some objects, like the painting screens and scrolls in Fudo Castle cannot be picked up.
Corpse: Killing an enemy will leave their corpse behind. A corpse will put other enemies on alert if they spot it, and running into them can make players and enemies alike trip. If a corpse is left alone and unwatched for enough time they will dissappear.
Explosive barrel and bomb: Found in "fortress" type maps, this special kind of object can be picked up and, if thrown, cause a loud explosion that will damage anyone near it. Explosive barrels come in small and large varieties, and bombs only appear in large varieties. Falling from altitude will also detonate them, as well as ramming or tripping into them.
Wall cannon: Funcionally they are considered traps, they are often set as a fixture in walls. If a player or enemy is nearby they will activate, launching spiked balls that cause damage and detonate after a period of time or if they slam hard enough against objects, walls or NPC. The activation of a wall cannon always makes nearby NPC curious. They cannot be picked up.

Explosive barrels and wall cannons can be bought and placed in a garden.

Also, collecting all posible decorative objects in the game will reward the player with a statue of Goh to set in the garden.

Walls[]

Walls are a common feature in all maps. Besides the expected obstacles of walls, clumsy players can slam against walls while sprinting (pressing "O") which causes enemies to check the source of the noise and, if the player slams often or with enough force, knock them unconscious for a few seconds.

Players can silently slide along walls if they press L1 (crouch) near them. A special stealth kill animation will play if the player catches an enemy near a wall without being detected.

A common bug in the game is for enemies to become stuck in walls while trying to return to their patrol posts.

Watchtowers[]

Some maps, specifically maps of the "town", "fortress" and "castle" type have watchtowers set on strategic locations. The towers themselves ofter have a soldier on watch. What truly makes the towers dangerous is that in the case a soldier manages to spot the ninja they can use the tower's bell to alert their allies of the ninja's presence, making them inmediately rush to the site the bell was rung and counting them as witnesses in the mission's score.

There are two types of watchtowers:

Wood towers: The more common type of atchpost found in the game. They are large wooden structures located near entrances in maps. They are equipped with a bell to alert of enemies and a ladder used by soldiers to reach the bell if they fall/were not at guard on top of the tower (the player cannot climb this ladder). Usually a grapple hook is neccesary to reach the top.
Two-floor watchposts: Found in Utakata Castle and Fudo Castle, these are two-floor buildings that surround the castle. They are almost always guaranteed to have a soldier on guard. Like wood towers they are equipped with a bell to alert of enemies but unlike wood towers they have no ladder to climb which can make it difficult and slower for soldiers to reach the bell, and for the ninja themselves do not need more than a few jumps to reach.

A wooden watchtower is one of the items players can buy and set in their garden.

Sliding Doors[]

These are a common feature in some maps, specifically found in Utakata Castle, Fudo Castle, Negishi Pavillion, Honcho Shimoyashiki and a small storage room in Mokuami Fortress. These are simple doors which can be completely opened by pressing Triangle or be slightly opened to spy by lightly pressing Triangle.

A special stealth kill animation will play if the player kills an unsuspecting enemy from behind a door. This will completely destroy the door, same as slashing it. Same as walls, an special steath kill animation will play if the player kills an unsuspecting enemy from the corner of an opened door. Jumping into, ramming or pulling the door with the grapple hook will push it from its hinges, functionally destroying it.

Slightly opening a door will not conceal the player as a closed door does. If the player has their back to the wall of the corner of a door they will not be seen. If the are direcly in front of it, either standing or crouched, an enemy might become curious and get closer or instantly become alert of the player's presence.

If an enemy spots a destroyed door they will become alert.

Be careful when you use doors to hide from alert Yojimbos, they have a tendency to destroy doors while searching for enemies.

Cats[]

Stray cats may appear in some areas, mostly "town" type maps but can also appear in "forest", "mountain" and the Asuka Village. Their function is similar to dog kennels: while not an inmediate hazard, if the player gets close to them they will flee, alerting any enemy who sees the cat run.

Unlike dog kennels there is no way to prevent them from fleeing other than simply not getting close to them.