Instead of the synergy bonus, you can make a Synergy Roll that can potentially apply a fluid bonus to your primary roll. The Synergy Roll is, in effect, an Aid Another check except that you are Aiding yourself. You roll a secondary skill in order to Aid a primary skill. There are no set synergy matches in this system. You (the player) bring it up in the moment, and it’s subject to the GM’s approval; GMs are entirely within their rights to say “no,” especially if you pour all your resources into just one skill and then argue that it helps with everything else. In this system, you don’t have to keep track of synergy on your character sheet, and it’s a little more flexible.
The DC for the Aid Self check is 10, which grants a +2 Synergy bonus. For every 5 points by which you exceed that DC, you get another +2. This roll could result in a lower bonus than you would receive under the standard rules, but it could also be a lot higher.
For example, if you want to use your superior Tumbling skills to help with a Jump check, you would roll your Jump check and an Aid Another check using your Tumbling bonus (to save time, roll them both at once). If your Tumble check were 23, you would get a +6 to your Jump check (i.e., you exceeded the DC by 13 points, which would yield an additional +2 on top of the +2 for meeting the DC).