Some of the ideas that have been shared for Cryptoliths in the Pre-Brainstorming thread:
- Porting over the rules from MtG directly, or making them climbable towers that can be destroyed.
- Giving them a forcefield aura that prevents people from being targeted by ranged normal attacks when within X spaces.
- Giving them a movement aura that slightly boosts the move of figures that begin their turn within X spaces.
- Giving them some kind of a negative effect, such as negating figures within X clear sight spaces or subtracting range.
- Making them teleportation beacons, so when a figure ends its move (or turn) adjacent to one, they can be placed on any empty space adjacent to another.
Of course, I may be missing some, so feel free to add any others.
Pretty much every idea meshes well with the Destructible Object angle, which is good in my opinion. There are some sketchy rules with the implementation of Destructible Objects in HeroScape, but it's a design space that we never truly saw explored outside of the Fortress Door, and now's the perfect opportunity to do that.
Of the ideas that have been proposed so far, my personal favorite is the teleportation beacons. That provides a new and unique tool to mapmakers, matches the clear sci-fi aesthetic of the Cryptoliths, and is very easy to remember (even though each tower will need its own card). My main issue with it is that it could deemphasize the DO aspect, since there will be less reason to destroy the towers if the important figures have already teleported.
Perhaps some kind of simple destruction rule could help by providing some reward beyond decreasing mobility for both armies, such as rolling an unblockable attack die against all adjacent figures when a Cryptolith is destroyed. We have precedent with terrain rules like this with the Lava Terrain, so it could be something to explore if we wanted to go that route.