Fighters and Unique Mechanics

I'm really happy with the unique mechanics I've developed for "elemental" (clerical?) magic as well as roguish gamblers. They aren't perfect, but I think they do a great job of using unique mechanics to support a special "feeling" for each character class or role.

I came up with another for "fighting men:" chess pieces! Chess pieces are great because they are very common gaming equipment as well as inexpensive: a set of basic plastic chessmen can be had for <$5. Basically, the fighting man starts with a 1/2 set worth of chessmen (i.e. all the blacks or all the whites). The fighting man may deploy a piece in order to gain a static, lasting benefit. He may sacrifice the piece in order to gain a burst benefit. And finally, he can deploy a piece to "summon" a hireling, man-at-arms, or other helpful ally.

The number of pieces that can be present at any given time should be limited, probably to an attribute -3.

However, once a piece is deployed, it cannot be "recalled;" if the player wants to get rid of it, it must be sacrificed. I'm not exactly sure how pieces should be restored; I am inclined to think that it should only be between adventures. After all, there are 20 pieces so they should last awhile.

Here's an example:

PAWN: Representative of foot soldiers. Some medieval scholars likened each pawn to a medieval profession, usually those of a commoner or artisan.

• Deployed: +1D to any mechanical art. At the end of each encounter, there is a 1/3 chance that a deployed pawn can be promoted to any other piece.
  
• Sacrifice: En-Passant. Lash out at a foe that disregards your zone of control and gain +1D on an opportunity attack.
  
• Summon: Minion, basic man-at-arms
  

One could also do something with the white vs. black pieces, similar to the red vs. black cards.