> Free invocations work like normal ones except in two ways: no fate points are exchanged, and you can stack them with a normal invocation for a better bonus. So you can use a free invocation and pay a fate point on the same aspect to get a +4 bonus instead of a +2, two rerolls instead of one, or you can add +4 to another character’s roll or increase passive opposition by +4. Or you could split the benefits, getting a reroll and a +2 bonus. You can also stack multiple free invocations together.