A marble trap can be built in the Trap space of the Dungeon in a player-owned house. It requires 84 Construction to build and when built, it gives 387 experience. The player must have a hammer and a saw in their inventory to build it.
This trap, if failed, will lower the player's agility level temporarily by 5 levels. If the player dodges the trap, they will gain 15 agility experience.
The marble trap has a 12% chance of being passed at level 1, 47% chance at level 50, and an 82% chance at level 99. This is a linear relationship. It is thus affected if your stats have been drained (i.e. by a different marble trap by 5, causing a reduction in 7% chance). This is the trap that caused a reduction in probability of passing other traps.
- ↑ https://twitter.com/JagexAsh/status/1264622042248286209?s=20