Gavindale: My fault - I should have indicated what game I am playing.... I am playing Ultima Underworld 1. You said that the runes remain active till removed or changed - what if I want to switch magic spells? Do I have to reconfigure the runes, or just select the desired spell from a list?
Edit: I just re-read your question. Tl;dr version is that you'll have to reconfigure the runes each time you want to ready a different spell for casting. I should mention that the runes will remain in the configuration that you set; if you set the runes in an order that doesn't form a spell, there won't be anything to cast. Also, holding the runes in the configuration for a particular spell doesn't mean that spell is active, it means you are ready to cast that spell. Just because you have the runes for "Resist Blows" selected does NOT mean the spell Resist Blows is active on your character. You can see which spells are active by their icons to the left of the compass.
Long version:
There is no spell list, per se. To have a spell ready to cast, open your rune bag and select the combination of runes that will generate that spell (every spell uses 2 or 3 runes, which must be selected in a particular order). When you have selected the runes and you want to cast the spell, then click on the runes that are currently "held" (they will have displayed in a box on the interface as you selected them). If you want to ready a different spell, open the rune bag and select the runes that will generate the different spell.
The main restrictions on casting any spell are the runes you have in your bag, your character level, your casting skill, and the amount of mana you currently have. If you don't have the necessary runes, if your level isn't high enough to cast spells of that circle, or if you don't have enough mana to cast the spell, then you can't cast the spell. If your Casting skill is low, you are more likely to either fail to cast the spell or to have the spell backfire and deal damage to you (both of these events will still spend the spell's mana cost).
For example, if you want to cast the spell "Create Food", you need to select the runes 'In', 'Mani', 'Ylem', in that order. Once those runes show up in the "spell casting" box, click on the box to try and cast the spell. If you have enough mana, the spell should work if there is room in front of you to create the food and if you have enough mana (don't try to cast this spell when you are standing in front of a wall or hill).
-If you failed to cast the spell, you'll get a message to that effect. Try again, or raise your Casting skill and try again.
-If you don't have enough mana to cast the spell, you'll get an appropriate message. If your max mana is high enough to afford the spell, then restore your mana in some fashion (sleeping, certain potions, or waiting long enough). If your max mana is too low to cast the spell, then raise your Mana skill.
-If the runes you have selected don't form a spell (ex. you selected Mani, Ylem, In), then you'll get an appropriate message. Select the correct runes in the correct order, then try again. There is a button in rune bag window if you need to return all of the currently held runes to the rune bag.
-If you aren't high enough level to cast the spell, you'll get an appropriate message. Level up, then try casting the spell again.
