GM Guidelines: Establishing Target Numbers

June 9, 2022

This post is part of the GM Guidelines series.

This is the first post in a series that may eventually become a standalone document. The posts in this series will provide advice for GMs. The VitalRPG system is intended to be flexible and the info in these posts are not firm rules, just guidelines that can be used if desired.

As a GM, you will frequently need to establish a TN when a character attempts an unopposed action where success is not guaranteed. Consider these examples:

A soldier kicks down a door.
A thief picks a lock during combat.
A mage casts a protection spell on the party before combat.

What TNs make sense for these actions? We’ll return to these examples as we discuss the guidelines further.

The first thing to consider is the relative difficulty of the action to the character’s background. This will provide a starting point:

TN2 → easy - These actions pose little challenge.
TN4 → medium - These actions are moderately difficult.
TN8 → hard - These actions are quite challenging.
TN16 → absurd - These actions are virtually impossible.

Next, consider any situational modifiers that make the action more difficult. These add +1 to the TN, some examples:

The action is during combat.
The action has multiple targets.
The action must be performed quickly.
The action must be performed without a key component.

Finally, consider any effect modifiers that make the action more difficult. These are discussed by the player and GM so that the gameplay outcome of the action is established if it succeeds. These add +1 to the TN, some examples:

The effect is greater than normal.
The effect lasts longer than normal.

Let’s return to our previous examples:

A soldier kicks down a door.
- Start with TN8 since the door is heavy, reinforced, and securely locked.
- There are no situational or effect modifiers.
- A final TN8 is established for the soldier.
A thief picks a lock during combat.
- Start with TN4 since it is a good quality lock.
- Add +1 since the action is during combat.
- Add +1 since the thief lost some important lock picking tools earlier in the adventure.
- There are no effect modifiers.
- A final TN6 is established for the thief.
A mage casts a protection spell on the party before combat.
- Start with TN2 since the mage is well trained in such spells.
- Add +1 for each additional target, three characters are targeted so +2.
- The spell normally lasts for three rounds but the player wants to increase it to five rounds, the GM allows this with +1.
- A final TN5 is established for the mage.

Try to be consistent and fair when establishing TNs. Remember, all character actions are made at the GM’s discretion. You can always say no to an action if it doesn’t make sense.

Dealing with the consequences of a failed action are important to keeping the game interesting and the story moving forward. We’ll dedicate another post in this series on that topic in the future.