Talking about magic, the classic system for GURPS is known as ‘spells as skills’ by many people. Here. magic is implemented through an extensive set of skills, each spell a separate skill. These are organised into colleges like ‘communication magic’, ‘fire magic’ and so on, and there are pre-requisite trees which mean that you generally need to learn the simpler spells in a college before you can learn the more advanced ones. There is a Magery advantage which is generally required to be able to cast spells, and this has multiple levels to it, adding to your intelligence stat for the purpose of casting spells. Again, more powerful / complex spells may require a certain level of Magery before you can learn them.
Initially, mages need to speak words and make gestures to cast spells, but as your overall skill increases this need reduces. High levels of skill also reduce the fatigue cost of spells. Spells consume fatigue, and mages usually learn a spell which helps them recover more quickly than others. There are also some cool things which allow you to generate energy for casting spells from things like waterfalls, which can create cool scenarios where mages seek out certain locations that could be tapped to fuel spell casting. There are rules for enchantment and ritual casting, too.
Magic is possibly more about flexibility than raw power in GURPS. As noted earlier, a skilled warrior is likely to generate more damage in combat than a wizard using direct attack magic. GURPS mages are usually more effective when they use their magic in battlefield control or buffing. So that presents a very different experience relative to D&D or similar magic.
That’s just one of the GURPS magic systems, and there is a full book dedicated (with multiple additional PDFs) to re-mixing the ‘spells as skills’ system to make it feel different in play. There are also several magic systems which use ‘spells as powers’ model, where spells are built more like in Hero, using their powers / advantages system. This gives a lot of flexibility and customisability, and since there are several you can confidently mix the ‘spells as powers’ systems together including divine, psionic, magical and more.
But there’s more! My favourite magic system for GURPS is Ritual Path Magic, which originally appeared in Monster Hunters (a modern day setting hunting vampires etc) but has become extremely popular and it now has standalone books covering it. This is a verb / noun system similar conceptually to Ars Magica, but very much its own thing. The verb governs base cost, while each noun is a skill. The system can be tuned to create magic which needs time to cast, with ritual trappings to boost success, or dialled up and powerful practitioners can do pretty much instantaneous magic. It’s great if you want a more low-magic fantasy in my opinion.
