with weaponmaster can I grab an attached gear on one of my units on a battlefield to a newly played unit without paying
Yes, you can use the Weaponmaster keyword to take an equipment currently attached to one of your units on a battlefield and attach it to the unit you just played. However, it is not necessarily "without paying."
According to Rule 821.1.c and related RiftJudge FAQs, Weaponmaster functions as follows:
- Cost Reduction: Weaponmaster allows you to pay the equipment's Equip cost reduced by [A] (1 power).
- Not necessarily free: It only becomes "free" (0 power) if the original Equip cost of the gear was exactly [A] (1 power). If the gear has an Equip cost higher than 1, you must still pay the remaining cost. If the gear has no Equip cost, Weaponmaster cannot be used.
- Transferring Gear: As confirmed by RiftJudge FAQ #8587 and Rule 747.1.b, a unit with Weaponmaster can indeed choose an equipment you control that is already attached to another unit you control and attach it to itself.
- Timing: This happens as a play effect when you play the unit with Weaponmaster.
In summary: You can move your own gear from one unit to the new one using the Weaponmaster ability, but you must pay the equipment's Equip cost minus 1 power.