coredump wrote:This is *not* an 'unwritten rule'
The base rules, the ones in the BRB, allow for a unit to move, or to stay still. Those are the rules, they are written, and the apply to all units.
Then the Nid codex says that some units will need to follow the IB rules.
It is not totally clear whether the IB rules totally replace the already allowed options, or if they are simply in addition to them.
I believe the 'alternately' indicates that they are totally replaced. But it is far from conclusive.
And those base rules are modified by the rules in the codex, allowing and/or disallowing some options that are normally available. In this case, the option to "normally" not do anything is superceded by the codex rule Insinctive Behavior, which only allows two options, test or lurk. It is quite clear that
IB replaces the "already allowed options", just as synapse replaces the "already allowed options" for Morale.