Regardless of who is casting a runic script, all practitioners of rune magic function the same way when using their scripts.
Learning Rune Magic[]
Only characters that have the rune magic class feature can learn runic spells. A rune spell is referred to as a “script”; those that employ rune magic are referred to as “scribes”. Each script has its own effect, description, and so on, as a normal spell.
Where clerics can choose from their entire list of spells each day, and a wizard can learn more spells and add them to their spellbook, a scribe must learn their scripts in advance. A scribe’s class level determines the number of scripts he can learn, what kind of scripts he can learn, and how often each day he may cast each of his prepared scripts, which is dependent on whether he is a major scribe, an intermediate scribe, or a lesser scribe (see Scribe Types). A scribe must have a casting ability score of at least 10 + a script’s level in order to learn or cast a script, and it must be a script on his script list. A learned script can be of any level he is capable of casting, so long as he knows at least one script of every level below that level. For example, should a 5th-level archivist wish to learn a 3rd-level script, he must already know a 1st-level and 2nd-level script.
Additionally, for every two levels a scribe gains (2nd, 4th, 6th, etc.) he can replace one of his scripts known for a different one. In effect, the scribe loses the old script in exchange for the new one. The new script’s level must be the same as that of the one being exchanged. A scribe may swap only a single script at any given level, and must choose whether or not to swap the script at the same time that they gain any new scripts known for the level.
Despite “knowing” his scripts, a scribe cannot simply cast magic as he wishes, as a sorcerer or oracle does. Rune magic is reliant upon the symbology of the runes themselves; as such, scribes must first create the rune to draw out its power.
Scribing a Rune[]
A runic script must be given form before it can be used. Typically, this means creating the rune upon a solid surface, though the method of creation can vary greatly from person to person. Unlike spells prepared by a wizard or cleric, runic scripts don’t have to be prepared again each day unless the scribe wishes to erase an existing rune and replace it with a new one.
Rest[]
To prepare runic scripts, a scribe must first sleep for 8 hours. The scribe does not have to slumber for every minute of the time, but he must refrain from movement, combat, casting scripts, skill use, conversation, or any other fairly demanding physical or mental task during the rest period. If his rest is interrupted, each interruption adds 1 hour to the total amount of time he has to rest in order to clear his mind, and he must have at least 1 hour of uninterrupted rest immediately prior to preparing his scripts. If the character does not need to sleep for some reason, he still must have 8 hours of restful calm before preparing any scripts.
Environment[]
To prepare a rune, a scribe must have enough peace, quiet, and comfort to allow for proper concentration. The scribe’s surroundings need not be luxurious, but they must be free from distractions. Exposure to inclement weather prevents the necessary concentration, as does any injury or failed saving throw the character might experience while studying.
Time[]
After resting, the scribe must prepare his runic scripts. Preparing all of his runes typically takes 1 hour. Preparing fewer runes takes a proportionally smaller amount of time, but always at least 15 minutes.
Choosing Runes[]
The scribe must choose which runes he wishes to create. Each rune must be scribed separately, and they must be one of his known scripts. The number of runes the scribe can prepare is based on his class level and whether he is a major scribe, an intermediate scribe, or a lesser scribe. His total number of scripts he can prepare each day is equal to the number of scripts he knows. The scribe can choose not to prepare his maximum allotment of runes for the day, instead leaving some available for preparation later. However, due to the compounding power of rune magic, this may not be ideal (see Scribing the Rune, below).
Scribing the Rune[]
When the scribe prepares his runic scripts, he must scribe it onto a surface. The exact method is largely up to the scribe, so long as the rune stays intact on an object. Most commonly, a scribe will choose to etch the rune into a suit of armor, a weapon, or a staff. Other methods such as ink drawings, sewing into fabric, or even pottery and sculptures can be used.
Scribing a rune imbues it with the caster’s own will and arcane essence; as such, only the scribe that created a rune can use it and bring forth its power.
A scribe does not have fixed spell slots, like most casters do. They instead are simply given an allotment of scripts prepared, which can be of any combination of level. A scribe can prepare a number of runes each day equal to the number of scripts he knows of 1st-level or higher. For example, a 5th-level intermediate scribe knows four scripts (excluding fundamentals), and therefor can prepare four runes per day which can be any combination, including preparing the same script multiple times.
Despite this flexibility in scribing, a scribe cannot have more scripts prepared of one level than he has of any level below it. For example, if a scribe wishes to prepare two 4th-level scripts, he must have prepared at least two 1st level scripts, two 2nd level scripts, and two 3rd level scripts.
A given script can be prepared multiple times. Each time a scribe does so, he gains an additional set of castings for that script for the day (see Casting a Script, below). As a scribe can cast his lower-level scripts more frequently than his higher-level scripts, it may prove advantageous to prepare multiple lower-level scripts as opposed to always preparing the highest level possible.
Keeping or Rewriting Scripts[]
As previously mentioned, runes do not have to be prepared every day (typically). As they are created upon a surface, as long as the object that a rune is upon is kept intact, the rune remains prepared indefinitely. Once the scribe rests for 8 hours, the runes recharge their magical power, granting the scribe his castings of that rune for the day.
Should the scribe wish to change his currently prepared scripts, he may do so, using the rules above. If he has no available runes, he can simply erase a previously-scribed rune to make room for the new one. However, he may not erase a script that he has already cast at least once that day. Once he does, he is stuck with the used script (whether it has castings remaining or not) for the rest of the day.
Casting a Script[]
In order to cast a script, you must first choose which script to cast. A scribe can only cast a script that he has prepared, and only if the object that the runic script was scribed upon is in his possession.
Runic scripts require a scribe to speak words of mystic power, which resonate with the etched rune. As such, you must be able to speak in order to cast a runic script (similar to a spell with a verbal component). Runic scripts also require you to have access to the object the rune was scribed upon; in essence, all scripts have a focus requirement of the object the rune was scribed upon. If you don’t have the object in question in your possession (or if it is destroyed), you cannot cast any scripts that are scribed upon it. If the object is broken (but not destroyed), you have a 30% chance for the casting to fail, causing you to lose the casting as if you failed to concentrate on it. Additionally, you must concentrate to cast a script. Runic scripts do not require somatic gestures, and as such armor and shields do not interfere with the casting of runic scripts. Runic scripts never have material components.
If a script has multiple versions, you choose which version to use when you cast it. You don’t have to learn a specific version of the script. The same applies to scripts with multiple types of overload.
A scribe does not have spell slots like a normal caster. Instead, he may cast each script that he has prepared a certain number of times each day, based on his class level and whether he is a major, intermediate, or lesser scribe (see Scribe Types). For example, a 5th-level archivist could cast each 1st-level script he has prepared twice each day, each 2nd-level script once each day, and each 3rd-level script he has prepared once each day.
Like a normal spellcaster, a scribe receives bonus scripts per day if he has a high ability score, as shown in the Ability Scores section in Chapter 1 of the Pathfinder Roleplaying Game Core Rulebook. These extra castings can be applied to any script he has prepared of the appropriate level. For example, an archivist with an Intelligence score of 20 gains two additional castings each day of 1st-level scripts he has prepared, plus an additional casting each day for scripts of 2nd, 3rd, 4th, and 5th levels. He must be able to cast a script of the given level to receive the extra castings each day.
These castings are not granted to each script he has prepared; rather, the scribe chooses which script to apply them to. In the above example, if the archivist has two 1st-level scripts prepared (say, augment and aegis), he can choose to gain two additional castings of augment, two additional castings of aegis, or one additional casting of each. He does not need to decide which script he wishes to apply his bonus castings to each day ahead of time.
Once a scribe has cast all of his daily castings of a given script, he cannot cast it again until he regains his daily castings. However, the scribe may still apply his bonus castings each day he receives for having a high ability score to a particular script, even if he has already used up his daily castings of that particular script.
Counterscript[]
It is possible to cast any script as a counterscript. By doing so, you are using the script’s energy to disrupt the casting of the same script by another character. This functions identically to counterspelling, save that the scribe uses his script to counter a script that someone else is casting.
Negation as a Counterscript[]
You can usually use negation to counterscript another script being cast without needing to identify the script being cast. Negation doesn’t always work as a counterscript (see the script description).
Counterspell vs. Counterscript[]
Generally, a spellcaster cannot counterspell a runic script, and a scribe cannot counterscript a spell, even if the scripts and spells have similar effects. However, dispel magic can counter runic scripts, and negation can counter spells, and the Improved Counterspell and Improved Counterscript feats can let you counter both (see Runic Designs vs. Schools of Magic).