Known Limitations

A few things the data format currently can't do. Knowing them up front saves time spent trying to make them work.

Costs can't go on a group

A selection group can't carry a cost. Put the cost on the selection entries inside the group instead.

Rules and profiles can't carry costs or constraints

Constraints can sit on selection entries, groups, forces, and categories, and costs on entries, forces, and categories, but a rule or a profile can't have either directly. If you need a cost or a limit tied to a rule, wrap it in a selection entry and put the cost or constraint on that entry. This one catches people out often, so reach for a selection entry whenever something needs a price or a limit.

Collective only affects display

The collective flag only changes how selections are shown; it validates nothing. When a unit mixes collective and non-collective selections, the models sit in individual stacks, and each stack can pick a different choice for a collective option. The roster is not flagged, even though a collective option is meant to be uniform across the unit. See Collective.

A condition can't read a characteristic value

Conditions can't read the numeric value of a characteristic. A rule can count how many of something are selected, or test categories, but it can't branch on a stat such as a model's Wounds or Strength.

Complex maths is awkward

Condition groups can do arithmetic (add, multiply, min/max, and comparisons), so simple calculations and checks are possible; see Condition-Group Maths. But there is no easy way to express anything complex: multi-step formulas are fiddly to assemble and hard to follow. Keep computed logic simple; if a rule needs elaborate maths, it is probably not worth forcing into the data.