Reserve is an action point mechanic that works well with Ultramicrolite20, but can work just as well with the Core Rules.
You have a Reserve equal to your MIND stat plus your highest skill. You spend it as follows:

Action	Cost	
Add 1d6 to a check			1	
Add 2d6 to a check			2	
Remove 1 hit/1d6 damage			1	
Take an extra action on your turn		2	
Cast a spell of the highest level you know 2	
Cast any other spell you know		1	

When you reach a new level of experience your Reserve Points reset back to equal your MIND stat. Any unused Reserve Points are lost.