In a nutshell: To give skill ranks more meaning, in various circumstances you’ll add your number of ranks in a skill to a roll.
Skill synergies no longer have prerequisites and don’t grant the same benefit. Instead, at any time you can add half your ranks in the benefactor skill of a synergy to checks made for the benefitted purpose of the synergy. Additionally, you can add your skill ranks to the following circumstances:
When you provoke an attack of opportunity for making a ranged attack while threatened, add your ranks in Balance and Tumble to your AC modifier. This is to represent that you can position yourself when firing in a way that makes you less vulnerable to being hit.
Battle Dancers and Monks add their ranks in a relevant Knowledge skill to their Weakening Strike ability.
You can add half of your combined ranks in any two of the following skills to all Truespeak checks: Knowledge (Arcana), Knowledge (Religion), or Knowledge (The Planes).
You can add half of your ranks in Decipher Script to Knowledge (Hypertechnology) checks made for hacking.
You can add half of your ranks in Open Lock to Use Magic Device checks made for hacking.
Ancient forms of hypertechnology can be found on rare occasion. Understanding and use of this technology is only partially associated with your other knowledge skills. It’s thus more a matter of intuition than memory to understand and use ancient Hypertechnology.
Your number of ranks applicable to checks to understand or use ancient technology is half of your combined ranks in:
- Knowledge (Arcana),
- Knowledge (Architecture and Engineering),
- Knowledge (Hypertechnology), and
- Knowledge (Xenolore).
If half of your combined ranks is at least 1, you can make checks regarding ancient hypertechnology. This skill uses your wisdom bonus or your intelligence bonus, whichever is higher.