Designing a Trap
To design a new trap, decide what CR you want the trap to have and consult Table 11–14: Trap Statistics on page 412 for guidance on the various statistics of a trap at that CR. These are only guidelines, however. Feel free to adjust a trap’s statistics, though you should avoid changing these numbers to values corresponding to a CR more than 2 higher or lower than the trap’s CR.
- Perception and Disable DCs: All traps require Perception and disable DCs. If the trap requires multiple checks to disable, use the DC for a trap with a CR 2 lower than your trap. If the trap has a bypass mechanism, use this DC for detecting and disabling the bypass as well.
- Initiative: If it is important when your trap acts in combat, use this bonus to calculate the trap’s initiative.
- EAC/KAC: If the mechanical parts of your trap can be attacked, these values help determine how easy they are to hit.
- Good and Poor Saves: If PCs use special attacks that can target objects against the trap, these values can be used for the trap’s Fortitude and Reflex saves. You decide which is a good save and which is a poor save for your trap. Traps don’t normally need Will saves, but if necessary, a trap’s Will save is a poor save.
- HP: Crucial parts of some traps can be damaged and should have the listed number of Hit Points. Traps are immune to anything an object is immune to unless otherwise noted. Traps also have hardness based on their material. A trap reduced to 0 HP is destroyed. Destroying a trap might set off a final component of the trap, like an explosion. Traps never have Stamina Points.
- Attack and Damage: The table lists the trap’s attack bonus and its average damage, if any, but consider reducing this damage if a trap has multiple attacks or affects multiple targets.
- Save DC: If a trap affects its victims by means of an area effect, a spell, a poison, or another special ability, use the listed DC for the appropriate saving throw.
| CR | Perception DC | Disable DC | Initiative | EAC/KAC | Good Save | Poor Save | HP | Attack | Damage | Save DC |
|---|---|---|---|---|---|---|---|---|---|---|
| 1/2 | 17 | 12 | +4 | 9/13 | +3 | +0 | 12 | +9 | 2d6 | 11 |
| 1 | 21 | 16 | +6 | 10/14 | +4 | +1 | 19 | +11 | 3d6 | 12 |
| 2 | 23 | 18 | +7 | 12/16 | +5 | +2 | 25 | +12 | 4d6 | 13 |
| 3 | 24 | 19 | +8 | 13/17 | +6 | +3 | 38 | +13 | 6d6 | 14 |
| 4 | 26 | 21 | +9 | 15/19 | +7 | +4 | 50 | +14 | 4d10+2 | 15 |
| 5 | 27 | 22 | +10 | 16/20 | +8 | +5 | 69 | +15 | 4d12+4 | 15 |
| 6 | 29 | 24 | +11 | 17/21 | +9 | +6 | 88 | +17 | 6d12 | 16 |
| 7 | 30 | 25 | +12 | 18/22 | +10 | +7 | 107 | +19 | 8d10 | 17 |
| 8 | 32 | 27 | +14 | 19/23 | +11 | +8 | 125 | +20 | 8d12 | 18 |
| 9 | 33 | 28 | +15 | 21/25 | +12 | +9 | 144 | +22 | 10d10+5 | 18 |
| 10 | 35 | 30 | +16 | 22/26 | +13 | +10 | 163 | +23 | 10d12 | 19 |
| 11 | 36 | 31 | +17 | 23/27 | +14 | +11 | 181 | +24 | 12d12 | 20 |
| 12 | 38 | 33 | +19 | 25/29 | +15 | +12 | 200 | +27 | 12d12+5 | 21 |
| 13 | 39 | 34 | +20 | 26/30 | +16 | +13 | 225 | +28 | 14d12 | 21 |
| 14 | 41 | 36 | +21 | 27/31 | +17 | +14 | 250 | +29 | 14d12+7 | 22 |
| 15 | 42 | 37 | +22 | 28/32 | +18 | +15 | 275 | +30 | 14d12+15 | 23 |
| 16 | 44 | 39 | +23 | 29/33 | +19 | +16 | 300 | +31 | 16d12+15 | 24 |
| 17 | 45 | 40 | +24 | 30/34 | +20 | +17 | 338 | +32 | 16d12+30 | 24 |
| 18 | 47 | 42 | +26 | 31/35 | +21 | +18 | 375 | +33 | 16d12+45 | 25 |
| 19 | 48 | 43 | +27 | 32/36 | +22 | +19 | 413 | +34 | 16d12+60 | 26 |
| 20 | 50 | 45 | +28 | 34/38 | +23 | +20 | 463 | +35 | 16d12+75 | 27 |
Source
Core Rulebook pg. 411
