There are a number of skills that can be learnt during role plays. Most of them are enhanced if you have a particular item, and that can help you learn, like Flight and Invisibility. Others are easier to learn, from practise, or simply buying a particular item. Some just come randomly during your role play. They all have different uses and different rules.

FLIGHT
Level 0 - No flight possible.
Level 1 (Automatically gained once you own a FLIGHT SKILL item) - Extends your leaps and jumps.
Level 2 - Short levitation
Level 3 - Levitation and very low flying over ground.
Level 4 - Medium flying, a foot off the ground (not water or air)
Level 5 - Some simple flying, up to your own height off the ground.
Level 6 - Simple flying, up to treetop height
Level 7 - Simple flying, unlimited height.
Level 8 - Fast flying at good speeds
Level 9 - Dives, wheels, loop-the-loops.
Level 10 - Ultimate Flight.

INVISIBILITY
Level 0 - No invisibility.
Level 1 - (Automatically gained when buying an INVISIBILITY SKILL item) Hiding skill improved
Level 2 - Very good hiding skill
Level 3 - Amazing hiding skill, able to hide in grass and small places
Level 4 - Ability to be silent and blend in, camouflaged.
Level 5 - Ability to fade away for a short amount of time (1 post)
Level 6 - Can disappear for a short amount of time (1 post)
Level 7 - Can disappear for a medium amount of time (3 posts)
Level 8 - Can disappear for a medium amount of time (5 posts)
Level 9 - Can disappear for a long amount of time (10 posts)
Level 10 - The ability to disappear at will, ultimate Invisibility for unlimited time.