Solo difficulties were added to many quests and dungeons a while back, but if you ask me around level 4-5 it becomes obvious that all they did was scale everything back ~20% and call it a day. There are solo dungeons I could not possibly complete with any build, and on solo difficulty you can't bring along a hireling. You will need a group for these levels and for any major questlines, which don't even have solo difficulties.
You run around as you do in most games, click to target and left-click (IIRC) to autoattack. Combat is fluid, enemies will move around and so can you, but you have a -4 penalty to attack while moving. You can block with the shift key to give yourself DR, which improves greatly if you use a shield. If you have the tumble skill you can enter a roll while blocking to get through or away from enemies.
Most other abilities are button-driven. As you amass spells and action points and usable items, you will probably end up with multiple quickslot bars on your screen. There are 20 bars provided for this reason.
There isn't a climb skill and you don't climb walls. There's a jump skill that determines how high you can jump, and a swim skill that determines how long you can stay underwater. Skills like intimidate and diplomacy will increase or decrease your threat, and are also sometimes used as dialog cues, but really not very often. There are nearly as many skills as there are in 3.5, with the exception of knowledge skills and the addition of haggle, a skill that influences buy and sell prices.
Thanks for this.
I appreciate it.