Preventing skill point allocation base on conditions

[kain_abel_666]

I am trying to prevent players from being able to invest in certain skills once they have selected a certain other.

Each character starts with +2 to Mastery, a custom stat that allows them to invest in each trees passive mastery skill.
These mastery skills are required to be invested in prior to being able to select the starter skills.
The mastery allots the character +1 to Choice_1, a custom stat, and i want the skill allotment to require the player have this stat.
The mastery will also reduce the mastery stat so that players can only invest in 2 Mastery (trees) or chose only one (keeping one will add bonuses to skill damage via conditional synergies).

I haven't been able to find a way to block the investment of skill points - the skpoint column in Skills.txt helps me from advancing the skill level but it allows players to invest(waste) point in the skills with no benefit.

I remember this feature in LRdO with their passives and i wish i could figure it out.

Any help would be much appreciated.

[Cypress]

You don't need to use precious stats/states on that, you can reference the base skill level instead. All you need to do is make a conditional that sets the required skill points to an unattainably high value, like 999, when you have invested into the defined skills.