Casting Subtlety
When a Mage or a Priest wants to cast a spell one of the factors to be considered is Spell Subtlety.
Spell Subtlety is a rating of each spell based on several factors and characteristic. When the spellcaster invokes the spell the person they are casting the spell at or in front of may or may not realize that magic is being used. This mechanic give a quick resolution to see who notices when a spell is cast.
In many situations, a wizard or priest does not care who sees him casting a spell. When a mage is getting ready to electrocute a band of ogres with his chain lightning spell, he usually doesn’t take any steps to conceal what he is doing and casts the spell in the most expedient fashion possible. On the other hand, some situations require great delicacy on the part of the character. When a wizard wants to charm a guard captain in front of the captain’s detachment of soldiers, he’ll have to be very careful not to tip his hand.
Naturally, some spells are more subtle than others. There are a number of factors to take into consideration - the number of components required, the size of the material components, the length of the casting time, and whether or not the spell requires some unusual behavior or speech on the part of the caster.
Noticing Spells: Who notices when spells are being cast? Generally, anyone who is directly observing the caster notices the strange gestures or air of concentration that characterize a spell. Depending on the lighting conditions and the amount of distractions nearby, an observer might be able to notice the spellcaster’s actions from as far as 30 to 50 feet away. Casual observers; people who are on the scene, but don’t have any particular reason to be watching the spellcaster, rarely notice the spell unless it’s unusually obvious. If it’s important to know whether or not a particular NPC or monster notices the spellcaster’s actions, the DM can make a Reason check for that character.
Subtlety Rating: A spell’s subtlety rating is the overall measure of how easily the caster’s actions are detected by an observer. In some cases, the spell is automatically detected; any character within 10 feet who specifically watches the spellcaster (for example, someone engaged in melee with the caster, or a vigilant guard) will automatically notice that the character is attempting a spell. However, if a reason check is used to determine whether or not a character notices a spell, the subtlety rating is used as a modifier to the character’s roll.
Spell Subtlety Modifiers to the Reason check.
| Modifier | Condition |
| +1 | Casting time of 4 or higher |
| +2 | Casting time of 7 or higher |
| +3 | Casting time of one round or more |
| +5 | Casting time of one day or more |
| +1 | Includes verbal component |
| +1 | Includes somatic component |
| +1 | Per three material components included |
| +1 | Spell includes unusual action (singing, clapping, etc.) |
| +2 | Spell requires dramatic action (shattering gem or breaking item, capering and dancing, shouting, etc.) |
| +4 | Spell requires very obvious action (a full religious ritual, drawing a circle on the ground with powder, etc.) |
| +6 | Character going out of his way to be noticed |
| –2 | Poor lighting |
| –1 | Background noise can mask sounds |
| –2 | Distracting activity nearby |
For a mage casting a spell with Verbal, Somatic and Material components and a short casting time the observer would get a +3 to their reason check to see if they notice the actions of the spell caster.
Casting time is an important factor in the subtlety of a spell, since the longer the character is involved in the spell, the more likely it is that someone will notice him. The number of components involved measures how complicated the spell is and how difficult it is to cast. Last but not least, some spells clearly require some unusual actions or behaviors that may be hard to disguise. However, if the caster can mask his actions by performing them in a place or manner that wouldn’t be suspicious (for example, dancing or clapping in a street carnival, or shouting on a crowded battlefield) this last modifier might be negated.
The spell’s subtlety rating is the total of its modifiers. It is applied to an observer who rolls a reason check to see if he or she notices the physical act of spellcasting. Remember, in some cases a check is completely unnecessary: a wizard who casts a spell in a pitch black room won’t be seen by anyone, while a priest who uses magic in a crowded town market is probably going to be noticed by someone nearby.
Note that characters can sometimes deceive intelligent enemies by pretending to cast spells. The would be trickster should have some idea of what he’s doing; otherwise he’s just flailing his arms around and shouting nonsense (which might be a distraction in and of itself!) It also helps a lot if the target of the charade has seen that particular character use magic before since the whole act is much more credible when it follows a real spell. Consider how fast a band of trolls might scatter if they’d just been fire balled and then observe the same wizard getting ready to cast another spell!
