Shinobi Iri or Art of Stealthy Entering
By Kuseru

An advanced version of the Art of Stealth, this ability focuses on being able to enter buildings and structures quietly and without being seen. Training also includes the balance necessary to traverse a variety of obstacles, such as strung ropes, tight ropes, narrow ledges and roof tops, as well as being able to stand on, and even fight from the tops of narrow poles and posts.
The character must have a climbing, prowl, and swimming skills (in addition to the required sense of balance listed below) to take this power. However, the character does not need to roll prowl or climbing when entering a structure so long as the character is in the dark and unsuspected. If the character's area is subject to inspection, then the chance to remain undetected is 25%+3% per level of experience. This power also gives the character the skill to silently cross moats and other water boundaries silently as well as to enter and leave the water silently. Also useful is the skill of being able to leave water and further sneak into a structure without leaving tell-tale water traces along the character's path. Base skill is 35%+4% per level of experience for entering, crossing, and leaving water undetected. Note: If the character has the Art of Stealth martial art power, they can use those prowl and water skill percentages while using this martial art power.
Due to the balance requirements of this power, it cannot be learned by anyone with a sense of balance skill of less than 80%. However, Maintain Balance can also be used to determine if the character has the sense of balance required, for every +1 to Maintain Balance, the character receives a +5% chance toward their sense of balance skill. In normal situations, such as walking at one fourth the character's normal Speed on narrow surfaces, they do not have to roll against their balance to successfully navigate the surface. Engaging in combat, attempting to walk faster or run, or jumps and leaps to and from these surfaces require a roll against the modified sense of balance skill, with the following cumulative penalties:
Attempting to walk at half the character's normal speed -15%
Attempting to walk at the character's normal speed -20%
Attempting to run on the surface -30%
Attempting to jump or leap to or from the surface -40%
Attempting to dodge or avoid a trap while traversing the surface -40%
Engaging in combat on the surface -40%
These penalties are reduced by 5% per level of experience, after the first level that the character takes this martial art power. In situations where more than one penalty applies (for instance, attempting to run while engaging in combat on a surface where the total penalty is -80%), the penalties are combined BEFORE the reduction is applied. For example, a tenth level character who received this skill at fifth level (the first level they had the sense of balance percentage needed, and could take a new martial art power) attempting to run while engaging in combat on a narrow wall top has a normal 98% chance for sense of balance and a -25% penalty reduction against the combined penalties of -80% for engaging in combat while running on a narrow surface would have a resulting skill percentage of 43%. Failure means the character has lost their balance and fallen.