Ablative Barrier is an early-game gearcheck and late-game non-agenda installer/unarchiver.

Design:

• Threat-gated “when rezzed” effects, like Threat-gated operations, play differently than Threat-gated repeatable/continuous abilities (Jaguarundi’s “when encountered”, Vovô Ozetti’s static abilities, and so on). This means that by the mid-game, when choosing whether to rez or even install Ablative, you'll be weighing “now” against “more”.

• Install 1 card from HQ or Archives is narrowed with non-agenda and in the root of or protecting another server. This keeps the rez cost (and threat level) low, and lets you play more with (still broad) subsets of a (super broad) effect, to weave a distinct texture.

For example, you can bring back the (self-trashing and easily-trashable) Rashida Jaheem (which, against a run-last-click, reads When you rez this ice, draw 3 cards and gain $3.!); but you cannot sneak in a Project Vitruvius, nor can you ice up the current server with a Magnet.

Compare:

• Drafter and Ansel 1.0.
• Echo, Tatu-Bola, and Ping.

(Tatu-Bola being Jinteki's 1↳-and-1s-for-$2 ETR ice with some “post-ETR” value.)

By the way, any gearcheck can (implicitly) act like a Pulse trigger, since they waste the click spent on that run (by ending it), which synergizes with click-taxing (in HB esp.).

When you rez this ice during a run 
against this server, the Runner loses [click].

Flavor: In Pathfinder, an "ablative barrier" is a spell that blocks things and pushes them away.

Invisible layers of solid force surround and protect the target, granting that target a +2 armor bonus to AC. Additionally, the first 5 points of lethal damage the target takes from each attack are converted into nonlethal damage.